Water-dispersible cellulose and process for producing the same

ABSTRACT

A material is provided to give food products sufficient viscosity and stability (heat resistance, stable suspension, etc.). The material is produced from an inexpensive raw material by an economical process. Further, a novel gel containing cellulose as the main component is also provided. 
     The present invention provides a fine fibrous water-dispersible cellulose derived from plant cell walls. For the production, a raw material having specific properties is used, and size reduction is carried out stepwise thereto. The water-dispersible cellulose can also be made into a dry composition by compounding with a water-soluble polymer or the like. This dry composition forms a gel when combined with a polysaccharide such as glucomannan or the like. The gel excels in heat-resistance and shape-retention and can be used to produce to novel food products.

TECHNICAL FIELD

The present invention relates to a water-dispersible cellulose, a drycomposition thereof, and a process for producing the same. Further, thepresent invention mainly relates to a novel gel composition whichprovides food products in the form of a liquid, sol, gel, paste, orsolid with stability with respect to heat resistance, emulsification,suspension, thickening, shelf life, etc. and further with an improvedmouth-feel and heat resistance. The present invention also rebtes to asponge-like gel having a novel mouth-feel.

BACKGROUND ART

Cellulose type materials are known for use in food products, cellulosepowder, microcrystalline cellulose, microfibrillated cellulose (MFC),microbial cellulose (bacteria cellulose, microreticulated cellulose),etc.

Cellulose powder has a large particle size. Accordingly, when blendedinto a food product that has a low solids concentration, such as drinks,or a food product with a soft mouth-feel, cellulose powder often gives arough feel upon eating. Thus, its use is limited to shredded cheese (forthe prevention of coagulation), cookies (for the improvement of shaperetention upon baking), etc.

With respect to microcrystalline cellulose, a new grade ofmicrocrystalline cellulose that disintegrates into small particles inwater has been developed. It hardly gives a rough feeling andparticularly serves to provide, among others, suspension stability forliquid food products. However, it is characterized by relatively lowviscosity, so that it has to be used in a great amount when used as athickener.

As microfibrillated cellulose, those disclosed in JP-A-56-100801,JP-A-61-215601, JP-A-60-186548, JP-A-9-59302, etc. are known. These arefundamentally produced by passing a suspension of cellulose materialthrough an orifice with a small diameter a number of times whileapplying a pressure difference of 3,000-8,000 psi (about 21 to about 56MPa) or 100 kg/cm² (about 10 MPa) or more. However, under such apressure difference, microfibrillation cannot progress sufficiently evenif the treatment is repeated many times, a large amount of materialremains. Accordingly, the mouth feel is adversely affected by the roughand grating feeling. Further, since the absolute quantity of themicrofibrillated component is small, it cannot give sufficient viscosityand stability to a food product in many cases.

As a further improvement of the above-mentioned technique,super-microfibrillated cellulose can be referred to, as inJP-A-8-284090. First of all, in this technique, pulp is used as astarting material and it does not matter whatever the species of theoriginal tree is and whatever the method of pulp making is. The startingpulp is preliminarily beaten with a beating machine (beater, Jordin,conical refiner, single disk refiner, double disk refiner, etc.). Whenthe number-average fiber length as measured by the fiber lengthdistribution measurement device (FS-200) manufactured by KAJAANI Co. is0.8 mm or more, the preliminary beating is carried out until thefreeness reaches 400 ml CSF or less. When the number-average fiberlength is less than 0.8 mm, the preliminary beating is carried out untilfreeness reaches 600 ml CFS or less. Then, using an abrasive grain platetype grinding apparatus equipped with an abrasive grain plate composedof abrasive grains having a grain size of No. 16-120 (“Super-grindell”manufactured by Masukou Sangyo K. K.), the freeness is reduced to 300 mlCSF or less. Further, by processing it with a high pressure homogenizer(“Nanomizer” manufactured by Nanomizer Co., Ltd.; “Microfluidizer”manufactured by Microfluidics Co., Ltd.; etc.) at a pressure of500-2,000 kg/cm² (about 49-196 MPa), a “super microfibrillatedcellulose” having a water retention of 350% or more as determinedaccording to the method indicated in JAPAN TAPPI No. 26, and anumber-average fiber length of 0.05-0.1 mm, wherein 95% or more of theintegrated fiber number based on the total fiber number has anumber-average fiber length of 0.25 mm or less, and the axial ratio ofthe fiber is 50 or more, can be prepared. According to the JP-A-8-284090reference, the cellulose particle has “a fiber width of 1 μm or less andthe shortest fiber has a fiber length of about 50 μm” as measured by adirect observation using an optical microscope and an electronmicroscope and, thus, “the axial ratio is 50 or more”.

Although this super-microfibrillated cellulose is suitable for use as anadditive to be blended into a coating material for the manufacture ofcoated paper or a dye or pigment carrier for the manufacture of dyedpaper, it contains too large an amount of thick and long fiber componentto be used as a material for food products. On the other hand, since thecontent of fine components that is stably suspensible in water is toolow, it fails to give a sufficient stabilizing effect on food products,and, further, gives an unpleasant mouth feel such as roughness to foodproducts. Regarding the fineness of fiber and water-suspension stabilitybrought about thereby, the applicability of the fiber as a material forfood products is limited, unless the fineness reaches such a degree thatthe openings of sieves are clogged making the measurement impossible.Alternatively, all the components pass through the sieve makingimpossible to obtain any value in the filtration for the water retentionmeasurement as prescribed in JAPAN TAPPI No. 26.

There has also been disclosed a microfibrillated cellulose prepared frombeet pulp (JP-A-11-501684). Although this substance is called“cellulose”, it is actually an associated substance of cellulose andpectin or hemicellulose present in beet pulp, which is a main cause ofits characteristics, such as high viscosity. Although the pectin and thehemicellulose are defined by “electric charging due to carboxylic acid”,their actual chemical compositions are unknown.

In JP-A-2000-503704, a composition is disclosed wherein cellulosenanofibril is obtained from cells comprising about 80% or more ofprimary wall and the other additives (30% by weight or less). Althoughthis “cellulose nanofibril” is regarded as substantially the sametechnique as in JP-A-11-501684, the only difference is that the use ofpure cellulose is disclosed. In the JP-A-11-501684 reference, themeaning of using “cells comprising primary wall” as a raw material seemsto lie in the degree of crystallinity. In other words, cellulosemicrofibril derived from secondary wall (for example, wood) has a highcrystallinity (higher than 70%) and therefore cannot be made thinnerthan several tens of nm to several μm. On the other hand, the mainobject of JP-A-11-501684 is “supplement addition to food products andthe like for the purpose of providing some functions of substantiallynon-crystalline (crystallinity 50% or less) cellulose nanofibril”.Accordingly, the “cellulose nanofibril obtained from cells comprisingprimary walls of about 80% or more” can be substantially interpreted as“that having a crystallinity of 50% or less”.

Microbial cellulose is also referred to by other names such as bacterialcellulose, bacterial microreticulated cellulose, and fermentationcellulose. Microbial celluloses are produced by the micro-organismsbelonging to Genus Acetobacter, Genus Gluconobacter, Genus Pseudomonas,Genus Agrobacterium, etc. This cellulose has a very high purity, and isreleased out of the microbial cells in the form of well-grownmicrofibril. For this reason, it is easy to purify and, as a result, theproduct has a high crystallinity and is useful as a material forcrystalline structural analysis of cellulose. Since the cellulose has aunique microfibril structure different from that of other plant cellwall-derived celluloses, its application for an acoustical material, apaper-making additive, and a food additive have been studied. In theapplication for food products, a thickening function or asuspension-stabilizing function have been recognized. There have beenattempts to add a specific polymeric substance to a medium for culturinga micro-organism, or to culture the mixture while agitating it, or todissociate the product thus obtained, or to use the product as are-dispersible dry powder (JP-A-3-157402, JP-A-8-291201, andJP-A-2000-512850). However, the production of cellulose by the cultureof micro-organism has not yet been established as an economicalproduction technique, since the problems of high cost, low productionspeed of cellulose, etc., remain unsolved.

It is an object of the present invention to provide a cellulosicmaterial capable of providing a sufficient thickening effect andstabilizing effect (namely, heat resistance, suspension stability andemulsion stability) to food products without adversely affecting themouth feel thereof by an economical process. Further, it is anotherobject of the present invention to provide a novel gel compositioncomposed mainly of cellulose.

SUMMARY OF THE INVENTION

The inventors have found that the problems mentioned above can be solvedby using a cellulosic material having specific properties, carrying outa stepwise size reduction, and preparing an aqueous dispersion ofmicrofibrillated cellulose having a specific dynamic viscoelasticity.

The present invention relates to the following embodiments.

A water-dispersible cellulose,

-   -   the cellulose being derived from a plant cell wall, crystalline        and fine fibrous, and having 30% by weight or more of a        component stably suspensible in water and having a loss tangent        of less than 1, when made into a 0.5% by weight aqueous        dispersion.

The water-dispersible cellulose includes 50% by weight or more of thecomponent stably suspensible in water and having the loss tangent ofless than 0.6, when made into a 0.5% by weight aqueous dispersion.

An aqueous suspension-form composition, having:

-   -   the water-dispersible cellulose mentioned above in an amount of        0.0005-7% by weight and water.

A water-dispersible dry composition, having:

-   -   the water-dispersible cellulose mentioned above in an amount of        50-95% by weight and a water-soluble polymer and/or a        hydrophilic substance in an amount of 5-50% by weight.

The water-dispersible dry composition further has a loss tangent of lessthan 1, when made into a 0.5% by weight aqueous dispersion.

In the water-dispersible dry composition mentioned above, thewater-soluble polymer is sodium carboxymethyl cellulose.

A gel-forming composition, having:

-   -   the water-dispersible dry composition mentioned above and at        least one polysaccharide selected from the group consisting of        alginic acids, galactomannan and glucomannan.

A gel composition, having:

-   -   the water-dispersible cellulose mentioned above, the aqueous        suspension-form composition also mentioned above or the        water-dispersible dry composition mentioned above as well, and        at least one polysaccharide selected from the group consisting        of alginic acids, galactomannan and glucomannan.

For the gel composition mentioned above, the polysaccharide isglucomannan, and the composition was a sponge-like structure and beedible.

A process for producing the water-dispersible cellulose or the aqueoussuspension-form composition, having at least the following steps (1) to(3):

-   (1) preparing an aqueous dispersion of a cellulose fibrous particle    having a length of 4 mm or less from a cellulosic substance derived    from a plant cell wall which has an average degree of polymerization    of 400 or higher and an α-cellulose content of 60-100% by weight,    provided that the cellulosic substance having an average degree of    polymerization lower than 1,300 and an α-cellulose content of more    than 90% by weight are excepted;-   (2) fiber-shortening and micronizing of the cellulose fibrous    particle in the aqueous dispersion of (1) so that a sedimentation    volume thereof becomes 70% by volume or more; and-   (3) treating the aqueous dispersion containing the cellulose fibrous    particle obtained in (2) by a high-pressure homogenizer at 60-414    MPa.

In step (3) of the above process, the concentration of the aqueousdispersion is 0.1-5% by weight, the pressure of the treatment is 70-250MPa, and the treatment is repeated 6 times or less.

In the process for producing the aqueous suspension-form composition,step (1) is further includes blending a water-soluble polymer and/or ahydrophilic substance.

In the process for producing an aqueous suspension-form composition, thewater-soluble polymer is sodium carboxymethyl cellulose.

A process for producing the water-dispersible dry composition, having atleast the following steps (1)-(5)

-   (1) preparing an aqueous dispersion of a cellulose fibrous particle    having a length of 4 mm or less from a cellulosic substance derived    from a plant cell wall which has an average degree of polymerization    of 400 or higher and an α-cellulose content of 60-100% by weight,    provided that the cellulosic substance having an average degree of    polymerization of lower than 1,300 and an α-cellulose content    exceeding 90% by weight are excepted;-   (2) fiber-shortening and micronizing the cellulose fibrous particle    in the aqueous dispersion of (1) so that a sedimentation volume    thereof becomes 70% by volume or more;-   (3) treating the aqueous dispersion containing the cellulose fibrous    particle obtained in (2) by a high-pressure homogenizer at 60-414    MPa;-   (4) blending a water-soluble polymer and/or a hydrophilic substance    into the aqueous dispersion treated in (3); and-   (5) drying the aqueous dispersion obtained in (4).

In the process for producing a water-dispersible dry compositionmentioned above, the water-soluble polymer is sodiumcarboxymethyl-cellulose.

A food composition, having:

-   -   the water-dispersible cellulose, the aqueous suspension-form        composition, the water-dispersible dry composition, or the        gel-forming composition.

A method for stabilizing a milk component-containing drink, having thefollowing steps:

-   -   blending the water-dispersible cellulose, the aqueous        suspension-form composition, or the water-dispersible dry        composition into the milk component-containing drink.

DETAILED DESCRIPTION OF THE INVENTION

Hereinbelow, various embodiments of the present invention will bedescribed in detail.

The water-dispersible cellulose proposed by the inventors may use, as astarting material, a cellulosic substance originating from the plantcell wall. Concretely, the industrially usable cellulosic substances,such as a pulp composed mainly of natural celluloses, such as woods fromconiferous trees, and broad leaved trees, cotton linter, kenaf, Manilahemp (abaca), sisal, jute, Savaii grass, esparto grass, bagasse, riceplant straw, wheat straw, reed, bamboo, etc, can be preferably used.Since these pulps composed mainly of natural cellulose are low in costand stably available, the products therefrom can be economicallysupplied to the market. Microbial cellulose which is a cellulosicsubstance not originating from the plant cell wall is not encompassed inthe starting material of the present invention, because there have beenproblems in the stability of its supply and cost.

Although raw cotton, papilus grass, paper mulberry, paper bush, gampi,etc., are also usable, their use is sometimes not preferred becausethese raw materials are difficult to obtain stably, they containnon-cellulose components in a large amount, and they are difficult tohandle. The same applies to the soft cell-derived starting materialssuch as beet pulp, fruit fiber pulp, etc. When regenerated cellulose isused as a starting material, no sufficient performance can be exhibited.Accordingly, regenerated cellulose is not included among the startingmaterials of the present invention.

The water-dispersible cellulose is composed fine-fibrous cellulose. Asused herein, the term “fine-fibrous” means that fiber length (majoraxis) is about 0.5 μm to 1 mm, fiber width (minor axis) is about 2 nm to60 μm, and the ratio of length to width (major axis/minor axis) is about5-400, as observed and measured by an optical microscope and an electronmicroscope.

The water-dispersible cellulose is crystalline. Concretely, thecrystallinity as measured on a dried sample by X ray diffraction method(Siegel method) exceeds 50%, and is preferably 55% or more. In the caseof the aqueous suspension-form composition, crystallinity is alsomeasured on dried sample. In the case of the water-dispersible drycomposition, the measurement of crystallinity is carried out on thecomposition as it is. When the sample contains a water-soluble polymeror the like, these components are non-crystalline, so that they arecounted as non-crystalline. Even in such cases, a water-dispersiblecellulose can be said to have a crystallinity exceeding 50%, as long asthe over-all crystallinity is 50% or more. If the overall crystallinityis 49%, for example, the water-dispersible cellulose must be separatedfrom other components to measure its crystallinity.

The water-dispersible cellulose of the present invention contains acomponent stably suspensible in water. As used herein, the term“component stably suspensible in water” concretely means a componentwhich is stably suspended in water without sedimentation, even when itis made into an aqueous dispersion having a concentration of 0.1% byweight and the resulting dispersion is centrifuged at 1,000 G for 5minutes. Such a component comprises a fibrous cellulose having a length(major axis) of 0.5-30 μm and a width (minor axis) of 2-600 nm, and alength/width ratio (major axis/minor axis) of 20-400, as observed andmeasured by a high-resolution scanning electron microscopy (SEM). Thewidth is preferably 100 nm or less and more preferably 50 nm or less.

Usually, an aqueous dispersion system of cellulose particles ischaracterized by white turbidity, and due to the whiteness it may beused as a clouding agent for food products. However, according to apreferable embodiment of the present invention in which almost allcomponents have a width of 100 nm or less, the optical transmission ofthe aqueous dispersion system increases and, thus, the transparencyincreases. The “component stably suspensible in water” constitutes themost important element of the present invention, which is the cause ofthe property of thickening the system, the property of stably suspendingsolid fine particles in water, the property of improving heat stabilityof emulsion system, the property of interacting with otherpolysaccharides to form a gel, etc.

The water-dispersible cellulose contains the “component stablysuspensible in water” in an amount of 30% by weight or more based on thetotal cellulose. If the content of the component is less than 30% byweight, the above-mentioned functions such as thickening, etc. cannot beexhibited sufficiently. The higher the content of this component, themore preferable. It is, however, more preferable that the content ofthis component is 50% by weight or more. For the aqueous suspension-formcomposition and water-dispersible dry composition of the presentinvention, 30% by weight or more of the total cellulose contained in thecomposition is the component that is stably suspensible in water.

The water-dispersible cellulose of the present invention, when made intoan aqueous dispersion having a concentration of 0.5% by weight, exhibitsa loss tangent (tan δ) of less than 1 and preferably less than 0.6, asmeasured at a strain 10% and frequency 10 rad/s. The value of losstangent indicates the dynamic viscoelasticity of an aqueous dispersion.The lower the value, the more gelatious the aqueous dispersion is. In anaqueous solution of polymer, the term “gel or gelations” is consideredto mean a state where the solute (polymer chain) forms athree-dimensional network structure to immobilize (solidify) the solvent(water). In the case of gel-forming water-soluble polymers, it isgenerally considered that loss tangent takes a value of 1 or more at alow concentration, while it decreases with any increase of the polymerconcentration to reach a value smaller than 1 at a gel-formingconcentration. On the other hand, the water-dispersible cellulose of thepresent invention, under the above-mentioned measurement conditions, hasa loss tangent smaller than 1, but has fluidity, so that it is not a gelin the true sense. That is, this means that, under a condition of lowstrain or low frequency, the dispersant (fine-fibrous cellulose) forms athree-dimensional network structure and exhibits a property ofsolidifying the dispersion medium (water), namely a gel nature. If theloss tangent is not smaller than 1, suspensibility and gel-formingproperty with other polysaccharides as mentioned hereinbelow becomeinferior. When the loss tangent is smaller than 0.6, these propertiesbecome further superior.

The water-dispersible cellulose of the present invention can be used notonly in the state of being mixed with a liquid (a dispersed state) butalso in the state of a solid (powder). The cellulose is preferably mixedwith water (dispersed in water). Although in this case the water contentis preferably smaller from the viewpoint of transportation, the watercontent of 80% by weight or more is preferable from the viewpoint ofease in blending (dispersing) the cellulose into water or food products.As liquids other than water, hydrophilic liquids, such as ethanol orglycerin can be used for a similar purpose. A preferable embodiment isan aqueous suspension-form composition in the form of a slurry or paste,comprising 0.0005-7% by weight of the water-dispersible cellulose andwater, which is excellent in handling property and blending propertyinto food products. When the amount of the water-dispersible celluloseis less than 0.0005% by weight, the composition is hardly different fromwater and there is no effect at all. When the amount of thewater-dispersible cellulose is more than 7% by weight, the compositionloses fluidity, so that it is difficult to handle.

Into the water-dispersible cellulose and aqueous suspension-formcomposition of the present invention, ingredients conventionally used infood products, such as a monosaccharide, an oligosaccharide, asugar-alcohol, a starch, a soluble starch, a starch hydrolyzate, an oilor a fat, a protein, a salt such as an edible salt and a variousphosphoric acid salt, an emulsifier, a thickener, a stabilizer, agelling agent, a souring agent, a preservative, a bactericide, anantioxidant, a fungicide, a pot-life improver, spices, food colors, andthe like may optionally be blended. In the case of the aqueoussuspension-form composition, however, such ingredients may be blended atmost in an amount of about 13% by weight. If the amount is more thanthat, the composition has too high a solids content as a whole, itsfluidity decreases, and it becomes difficult to handle. That is to say,in the case of the aqueous suspension-form composition, the preferablecomposition is: water-dispersible cellulose 0.0005-7% by weight; water80-99.9995% by weight; and other ingredients 0-13% by weight.

The water-dispersible cellulose and aqueous suspension-form compositionof the present invention are quite high in suspension stability inwater. Accordingly, their water-retention (JAPAN TAPPI Paper-PulpTesting Method No. 26) and freeness (JIS P 8121) cannot be measured bythe procedures applicable to prior microfibrillated cellulose.

To measure the water retention, when an aqueous suspension containingcellulose in the amount corresponding to an absolute dry weight of 0.5 gis poured into a metallic cup filter equipped with a metallic wire (φ20mm) having a sieve opening of 74 μm and the suspension is slowly suckedwith an aspirating device, a sample has to form a uniform mat. Evenunder such conditions, however, the products of the present inventioncannot form a mat because of clogging, or passing through the metallicwire. When the clogging takes place, even if it is subjected to asubsequent centrifugation at 3,000 G for 15 minutes, dehydration doesnot occur but a separate water layer is formed as an upper layer.

Further, the measurement of freeness (Canadian standard), involves afiltration with a brass sieving plate (with a thickness of 0.51 mm andholes with a diameter of 0.51 mm exist in a number of 969 per 1,000 mm²of the surface). In this measurement, the extent of beating of thecellulose fiber is evaluated on the basis of the fact that, when a 0.3%by weight aqueous dispersion of cellulose (pulp) fiber is passed throughthe sieve, the cellulose fiber is laminated on the sieve plate to changethe falling speed of water. When the freeness of the product of thepresent invention is measured, the water-dispersible cellulose passesthe sieve plate without remaining thereon. Though detailed descriptionis omitted here, freeness becomes smaller with the progress of beating(hereinafter, referred to as micro-fibrillation) of cellulose fiber.When the fiber becomes excessively short and thin as a pulp fiber forpaper making, the fiber comes to pass the sieve plate, and, thusgradually comes to have higher freeness. That is to say, with theprogress of micro-fibrillation, freeness decreases at first butincreases thereafter. Considering the purpose and principle of themeasurement, it is not appropriate to carry out such measurements in thecase where a cellulose fiber has become extremely fine.

Based on the above, it can be understood that, in the conventionalmicrofibrillated celluloses, the extent of the finess of the fiber isnot as high as that in the product of the present invention, becausewater-retention and freeness could be measured on the conventionalmicrofibrillated celluloses. Thus, it can be said that the product ofthe present invention is distinguished from the conventionalmicrofibrillated celluloses.

The water-dispersible dry composition of the present invention is a dryproduct comprising 50-95% by weight of a water-dispersible cellulose and5-50% by weight of a water-soluble polymer and/or a hydrophilicsubstance, and is in the form of granule, grain, powder, scale, smallscale, or sheet. This composition is characterized in that, when thecomposition is thrown into water and a mechanical shearing force isapplied thereto, the particles, etc. are disintegrated to allowmicrofibrillated cellulose to disperse into the water. When the contentof the water-dispersible cellulose is less than 50% by weight, theproportion of cellulose is too low to bring about an effect ofthickening, stabilization, etc. When the content of thewater-dispersible cellulose exceeds 95% by weight, the proportions ofother ingredients becomes relatively low and, thus, sufficientdispersibility in water cannot be ensured. From the viewpoint ofensuring the extent of the function to be provided and thedispersibility in water, a preferable amount of water-dispersiblecellulose to be blended is 65-90% by weight, and a preferable amount ofthe water-soluble polymer and/or hydrophilic substance to be blended is10-35% by weight.

For the conventional microfibrillated celluloses, it has also beenattempted to prepare a similar dry composition therefrom(JP-A-59-189141; JP-A-60-44537; JP-A-60-186548; JP-A-9-59301). All thedry compositions, however, when thrown into water, could not provide themicrofibrillated cellulose reconstituted to the state before the drying.This is considered to be due to insufficient micro-fibrillation of thefiber so that many branched bundles of fiber exist, which are apt to becornified (coalescence) at the time of drying. On the other hand, thewater-dispersible cellulose of the present invention has very finefibrous constitutional units and hardly contains branched bundles offiber.

It is therefore considered that the effect of preventing cornificationof the water-soluble polymer can act effectively. Probably for thisreason, the water-dispersible cellulose in the present invention isreadily reconstituted into a state comparable to that of before dryingby dispersion in water.

The water-soluble polymer used in the present invention is a substancehaving an activity of preventing the cornification of cellulose upondrying. Concretely, one, two or more substances selected from gumarabic, arabinogalactan, alginic acid and salts thereof, Curdlan, Gumghatti, carrageenan, karaya gum, agar, xanthan gum, guar gum,enzymatically-hydrolyzed guar gum, quince seed gum, gellan gum, gelatin,tamarind seed gum, indigestible dextrin, tragacanth gum, Furcellaran,pullulan, pectin, Locust bean gum, water-soluble soybean polysaccharide,sodium carboxymethyl cellulose, methylcellulose, sodium polyacrylate andthe like are used.

Among these substances, sodium carboxymethyl-cellulose is especiallypreferable. As the sodium carboxymethylcelllulose, those having thedegree of substitution of carboxymethyl groups of 0.5-1.5 and viscosity,when made into a 1% by weight aqueous solution, of about 5-9,000 mPa·sare preferably used, and those having the degree of substitution ofcarboxymethyl groups of 0.5-1.0 and viscosity, when made into a 1% byweight aqueous solution, of about 1,000-8,000 mPa·s are furtherpreferably used.

The hydrophilic substance used in the present invention means asubstance having a high solubility in cold water, hardly imparting aviscosity, and being solid at an ambient temperature. As the hydrophilicsubstance, one, two or more substances selected from dextrins,water-soluble sugars (glucose, fructose, sucrose, lactose, isomerizedsugar, xylose, trehalose, coupling sugar, paratinose, sorbose, reducedstarch-saccharified gluten, maltose, lactulose, fructo-oligosaccharide,galacto-oligosaccharide), sugar alcohols (xylitol, maltitol, mannitol,sorbitol, etc.) are used. As mentioned above, the water-soluble polymershave an effect of preventing the cornification of cellulose,nevertheless some of the water-soluble polymers are inferior inwater-conveying property into inner part of the dry composition.Accordingly, it is sometimes necessary to apply a stronger mechanicalshearing force for a longer period of time in order to disperse the drycomposition in water. On the other hand, the hydrophilic substancemainly enhances the water-conveying property, and concretely,accelerates the water-disintegrating property of the dry composition.Since dextrin works especially well in achieving this effects, the useof dextrin is preferred.

The dextrins used in the present invention are partial hydrolyzatesformed by hydrolyzing starch by an acid, an enzyme or heat, in which theglucose residues are combined through α-1,4 linkage and α-1,6 linkage.As expressed in terms of DE (dextrose equivalent), those having an DEvalue of about 2-42 are used in the present invention. Branched dextrinfrom which glucose and low molecular weight oligosaccharide have beenremoved can also be used.

Into the water-dispersible dry composition of the present invention,ingredients suitable for food products, such as a starch, an oil and afat, a protein, a salt such as an edible salt and various phosphoricacid salts, an emulsifier, a souring agent, a sweetening agent, a spice,a food color, and the like may be blended optionally, in addition to thewater-dispersible cellulose, water-soluble polymer and hydrophilicsubstance, for the purpose of improving suspension stability, flavor,appearance, and etc. The total amount of the individual ingredients isat most 85% by weight, and is determined in view of productivity, itsfunction, its price, etc.

As mentioned above, when the water-dispersible dry composition is throwninto water and a mechanical shearing force is applied thereto, theconstitutional units (such as the particles) are disintegrated and thefine-fibrous cellulose is dispersed in water. Therein, the mechanicalshearing force is applied by dispersing a 0.5% by weight aqueousdispersion with a rotational homogenizer at 15,000 rpm or less for 15minutes at temperature of 80° C. or lower

The aqueous dispersion thus obtained contains the “component stablysuspensible in water” in an amount of 30% by weight or more based on thetotal cellulose component. This aqueous dispersion shows a loss tangentsmaller than 1, at a concentration of 0.5% by weight. The method formeasuring the content of the “component stably suspensible in water” ina water-dispersible cellulose and the loss tangent will be mentionedlater. As mentioned above, the “component stably suspensible in water”in a water-dispersible cellulose has a major axis of 0.5-30 μm and aminor axis of 2-600 nm. The major axis/minor axis ratio is 20-400.Preferably, the width thereof is 100 nm or less, and more preferably 50nm or less.

Next, the methods for producing the water-dispersible cellulose, theaqueous suspension-form composition and the water-dispersible drycomposition of the present invention will be described below.

As mentioned above, a raw material for the water-dispersible celluloseof the present invention is cellulosic substance originating from plantcell wall. Herein, the general properties thereof will be explained. Forproducing the water-dispersible cellulose of the present inventionefficiently, it is preferable to use a cellulosic substance having anaverage degree of polymerization of 400 or higher and an α-cellulosecontent of 60-100% by weight. However, even if the properties satisfythe above-mentioned conditions, those having an average degree ofpolymerization lower than 1,300 and an α-cellulose content over 90% byweight at the same time are excepted. More preferably raw materials havean α-cellulose content of 85% by weight or less, and most preferably 75%by weight or less. Especially preferable raw materials include woodpulp, cotton linter pulp, wheat straw pulp and bamboo pulp. When theaverage degree of polymerization of a raw material is lower than 1,300and the content of α-cellulose exceeds 90% by weight, it is quitedifficult to make the cellulose have a loss tangent smaller than 1, whenmade into a 0.5% by weight aqueous dispersion (a method for measuring anaverage degree of polymerization and an α-cellulose content will bedescribed hereinbelow).

The important point in the method for producing a water-dispersiblecellulose of the present invention lies in, to express briefly,extracting the cellulose microfibril contained in the raw material inthe form, as micronized as possible, without fiber-shortening. As usedherein the term “fiber-shortening” means to make the fiber length ofcellulose microfibril short by the action of cutting, or the like, orthe state itself where the fiber has been shortened. The term“micronization” means to make the fiber diameter of cellulosemicrofibril thinner by the action of, for example, tearing, or the stateitself where the fiber diameter has been made thinner. According to thetechnique of the present day, the “micronization” process is more orless accompanied by a “fiber-shortening” process, as there is noapparatus available that can only produce “micronization” by providingonly a tearing action.

Particularly when the starting cellulosic substance has a low averagedegree of polymerization, “fiber-shortening” tends to occur. When themicronizing treatment is carried out until no coarse fiber is found, thefiber-shortening action simultaneously progresses. As a result, 0.5% byweight aqueous solution of the resulting fibrous cellulose comes to showa loss tangent of 1 or higher.

Further the α-cellulose content of the starting cellulosic substancealso influences the value of the loss tangent. That is, when the contentof α-cellulose is high, the “micronization” and the “fiber-shortening”simultaneously progress, so that the loss tangent, when made into a 0.5%by weight aqueous solution, is apt to be greater than 1, which is notdesirable. By the way, α-cellulose is insoluble in a 17.5% by weightaqueous solution of NaOH and is considered to have a relatively highdegree of polymerization and a high crystallinity. As the content ofcomponents other than α-cellulose contained in the starting cellulosicmaterial, namely β-cellulose, γ-cellulose, hemicellulose and the likeincreases, “micronization” tends to progress preferentially to“fiber-shortening”. Accordingly, when the content of the componentsother than α-cellulose increases, the loss tangent of the aqueousdispersion tends to become less than 1. Probably, this is presumablyattributed to the fact that the α-cellulose component constitutes thehighly crystalline microfibril component, while the other components arelocalized around the microfibril.

In the present invention, in order to make the “micronization” progresswhile suppressing the “fiber-shortening”, a starting cellulosic materialhaving a higher value of average degree of polymerization and a lowercontent of α-cellulose is preferably used. However, the α-cellulosecomponent is generally high in its degree of polymerization, and thuswhen the α-cellulose content is low, the average degree ofpolymerization tends to simultaneously be lower. Therefore, a detailedstudy is necessary to determine the optimum balance between them.

As a result of the study, it has been found that “micronization”progresses in preference to “fiber-shortening” when the α-cellulosecontent is 60-90% by weight, providing that the average degree ofpolymerization of the starting cellulosic substance is 400 or higher butlower than 1,300, and when the α-cellulose content is 60-100% by weight,providing that the average degree of polymerization of the startingcellulosic substance is 1,300 or higher. In this respect, a case wherethe content of α-cellulose is lower than 60% by weight is not suitablebecause the amount of the component capable of becoming themicro-fibrillated cellulose decreases relatively.

The starting material used in the present invention may be used afterbeing subjected to a pre-treatment for the purpose of promoting themicronization. As the method of the pre-treatment, for example,immersion in a dilute aqueous alkali solution (for example, 1 mol/Laqueous NaOH solution) for several hours, immersion in a dilute aqueousacid solution, an enzymatic treatment, breaking with explosion, etc.,can be included.

An example of the process for producing the water-dispersible celluloseof the present invention will be mentioned.

(1) Preparation of an Aqueous Dispersion of Cellulose Fibrous Particles

First, the starting cellulosic substance used in the present inventionis pulverized into fibrous particles having a length of 4 mm or less.Preferably, 50% or more of the total fibrous particles has a length ofabout 0.5 mm or more. More preferably, all the particles have a lengthof 3 mm or less, and most preferably all the particles have a length of2.5 mm or less. The method of pulverization may be either a dry processor a wet process. In the case of the dry process, a shredder, a hammermill, a pin mill, a ball mill, etc., can be used, while in the case ofthe wet process, a high speed rotational homogenizer, a cutter mill,etc. can be used. If necessary, the treatment is carried out afterprocessing the starting cellulosic material to have a size facilitatingthe feeding into each machine. The pulverizing treatment may be repeateda plurality of times. The use of a strong pulverizing machine, such as awet medium-agitation type pulverizer, is undesirable because it producesan excessively shortened fiber.

A preferable machine is a wet type Comitrol (URSCHEL LABORATORIES,Inc.). When Comitrol is used, the starting pulp is cut into a size of5-15 mm square, hydrated to a water content of about 72-85%, and thenthe material is thrown into an apparatus equipped with a cutting head ora micro-cut head to carry out the treatment.

Then, the fibrous particle thus obtained is thrown into water, anddispersed without coagulation by means of propeller-agitation,rotational homogenizer, or the like. In the case where the startingmaterials have short fiber particle length as a result of pulp-makingprocess, etc., it is sometimes possible to prepare an aqueous dispersionof fibrous particles having a length of 4 mm or less only by thisdispersing operation, without the above-mentioned pulverization using amill. In this dispersing operation, the concentration of cellulose inthe dispersion is preferably about 0.1 to 5% by weight. At the sametime, a water-soluble polymer and/or a hydrophilic substance may beadded for the purposes of stabilizing the suspension of the fibrousparticle or preventing the coagulation thereof. Blending of sodiumcarboxymethyl cellulose is one of the preferable embodiments.

(2) Fiber-Shortening and Micronization of Cellulose Fibrous Particles

The cellulose fibrous particles present in the aqueous dispersionobtained in (1) are subjected to a fiber-shortening treatment andmicronization, to some extent so as to make the sedimentation volume 70%by volume or more, and preferably 85% by volume or more. As used herein,the term “sedimentation volume” means the volume of a clouded suspensionlayer observed when dispersing fine cellulose fibrous particles in waterto obtain a uniform aqueous dispersion having a cellulose content of0.5% by weight, pouring 100 mL of the dispersion into a glass tube withan inner diameter of 25 mm, agitating the content by turning the tubeupside-down several times, and then allowing the tube to stand at anambient temperature for 4 hours.

The above-mentioned fiber-shortening and micronization can be carriedout by treating the aqueous dispersion obtained in (1) with anapparatus, such as a high speed rotational homogenizer, a piston typehomogenizer, a whetstone-rotation type pulverizer or the like. Apreferable apparatus is the whetstone rotation type pulverizer, which isa sort of the colloid mill or the stone mortar type pulverizer. Forexample, this is an apparatus in which whetstones composed of No. 16-120whetstone particles are ground together, and the above-mentioned aqueousdispersion is passed through the ground parts to enable the pulverizingtreatment. If necessary, this treatment may be repeated a plurality oftimes. In this case, changing whetstone to the ones having suitablesizes of whetstone particles is one of the preferred embodiment. Forexample, a whetstone rotation type pulverizer contributes to both“fiber-shortening” and “micronization”, and the proportions of thecontribution can be controlled by selecting the grain size of thewhetstone particles. Thus, when the fiber-shortening is of interest,whetstones of No. 46 or under are useful, whereas when the micronizationis of interest whetstones of No. 46 or above are effective. No. 46whetstone exhibits both of the actions. Concrete apparatuses includePure Fine Mill (Grinder Mill) (Kurita Kikai Seisakusho, Co., Ltd.), andCerendipitor, Supermasscolloidor, Supergrindell (all manufactured byMasukou Sangyo, Co., Ltd.), etc.

(3) High Pressure Homogenizer Treatment

An aqueous dispersion containing the fibrous cellulose particles whichhave been shortened and micronized in (2) is treated with a highpressure homogenizer at a pressure of 60-414 MPa to prepare awater-dispersible cellulose and an aqueous suspension-form composition.The treatment is repeated a plurality of times, if necessary. It is alsopossible to separate a finer cellulose component by centrifugation orthe like.

When the average degree of polymerization of the fibrous celluloseparticle is 2,000 or higher and the content of α-cellulose exceeds 90%by weight, it is sometimes necessary to repeat the high pressurehomogenizer treatment more than 10-20 times. Considering productionefficiency, however, it is desirable to suppress the number of thetreatments to 6 times or less by appropriately selecting the startingmaterial and the treating conditions of whetstone rotation typepulverizer in step (2).

Generally, when the number of the treatments is increased, viscosityincreases at first but thereafter decreases gradually. Probably, this isattributable to the fact that, the “micronization” reaches its upperlimit more rapidly than fiber-shortening as the number of the treatmentsincreases. After the viscosity of the system has risen until the limitof micronization has been reached, substantially only the“fiber-shortening” progresses with the increase in the number of thetreatments, to lower the viscosity of the system.

The micronization tends to progress more preferentially at a lowerconcentration of cellulose particles. As a result, the highestattainable value of apparent viscosity becomes higher and the losstangent becomes lower. A lower treating pressure similarly tends to givea higher maximum attainable viscosity and a lower loss tangent. It,however, necessiates an increase of the number of times of treatment,which results in a drop in productivity. In this case, the maximumattainable viscosity is difficult to reach when the content ofα-cellulose is high. Contrarily, when the treating pressure is high, themaximum attainable viscosity can be reached after fewer treatments, butunder such a condition the “fiber-shortening” readily progresses and theabsolute value of viscosity becomes much lower.

Based on the above-mentioned findings, the lower limit of the treatingpressure in the homogenizer in the present invention is 60 MPa, and itsupper limit is 414 MPa. When the pressure is lower than 60 MPa, the“micronization” cannot progress sufficiently, and the water-dispersiblecellulose of the present invention cannot be produced. At the presenttime, none of the apparatuses is found to produce a pressure exceeding414 MPa. The pressure is preferably 70-250 MPa, and more preferably80-150 MPa.

The cellulose particle concentration in the aqueous dispersion to betreated is preferably about 0.1-5% by weight and further preferably0.3-3% by weight.

The temperature of treatment may be appropriately selected from a rangeof about 5-95° C. Although the micronization progresses more readily ata higher treating temperature, the fiber shorten to a marked extent,depending on the kind of starting materials. For example, in the case ofwood pulp, micronization progresses and the viscosity readily increasesat 75° C. or higher, while in the cases of wheat straw pulp and bagassepulp, the viscosity tends to become low so that the treatment ispreferably carried out at 25-60° C.

Concretely, the apparatuses include: a pressure type homogenizer(Invensys APV Co., Izumi Food Machinery K.K., Sanwa Kikai K. K.),Emulsiflex (AVESTIN Inc.), Ultimizer System (Sugino Machine, Co., Ltd.),Nanomizer System (Nanomizer K. K.), Microfluidizer (MFIC Corp.), etc.

(4) Blending of Water Soluble Polymer and/or Hydrophilic Substance

To the aqueous dispersion treated according to (3), a water-solublepolymer and/or a hydrophilic substance may be added, if desired. Thewater-soluble polymer and/or hydrophilic substance may be added aftermaking them into an aqueous solution or in the form of powder as theyare. When they are added in the form of powder, coagulation tends tooccur and particularly when the solid concentration is high, theaddition of powder deteriorates fluidity, in which, therefore, asuitable agitator or a mixer is used appropriately.

(5) Drying

In producing the water-dispersible dry composition of the presentinvention, the aqueous dispersion obtained in (4) is dried by a knownmethod. A method which does not produce hard lumps of the dried materialis advisable. For example, a freeze-drying method, a spray dryingmethod, a tray drying method, a drum drying method, a belt dryingmethod, a fluidized bed drying method, a microwave drying method, aheat-generating fan type vacuum drying method, etc. are preferable. Ifthe drying is carried out at high temperature for a long period of time,the water-dispersibility is deteriorated. This is probably due to amarked progress of the cornification of the cellulose particles(fibers). From the viewpoint of water-dispersibility, the dryingtemperature is preferably 120° C. or lower and especially 110° C. orlower. The water content after the drying is preferably 15% by weight orless, further preferably 10% by weight or less, and most preferably 6%by weight or less, from the viewpoint of handling property andtime-stability. If the water content is less than 2% by weight, theproduct can be charged with static electricity, causing the powder tobecome difficult to handle.

The dried product is pulverized according to the need. As thepulverizer, a cutter mill, a hammer mill, a pin mill, a jet mill and thelike are used, and pulverization is carried out until the powder comesto pass thoroughly through a sieve having a mesh size of 2 mm. Morepreferably, the pulverization is carried out until the pulverizedproduct comes to pass nearly wholly through a sieve having a mesh sizeof 425 μm and, as an average, the particle size reaches 10-250 μm. Inthis manner, the water-dispersible dry composition can be produced.

The gel-forming composition, which is another embodiment of the presentinvention, can be obtained by mixing the water-dispersible drycomposition with at least one polysaccharide powder selected fromalginic acids, galactomannan and glucomannan. These powders are mixedaccording to a known method, namely by the use of a vessel-rotation typemixer (cylinder type, V type, double conical type, etc.), avessel-fixation type mixer (ribbon type, screw type, paddle type,planet-wise movement type, high speed flow type, rotating disk type,etc.), a fluidized mixer, an air stream agitation type mixer, etc. Themixing is carried out, roughly saying, at a proportion of 10-90% byweight of the water-dispersible dry composition and 90-10% by weight ofthe polysaccharide.

The water-dispersible cellulose, aqueous suspension-form composition,water-dispersible dry composition and gel-forming composition of thepresent invention obtained according to the above-mentioned methodscontain cellulose, which is a water-insoluble substance, as a maincomponent. Since the cellulose is in the form of a very fine fiber,however, it does not impart any rough mouth feel or powdery feel to afood product, when blended into the food product. Further, they areexcellent in the performances of thickening, shape-retention, suspensionstabilization, emulsion stabilization, heat stabilization(heat-resistant shape-retention, denaturation-prevention of proteins),and performance of imparting a body feel. These performances are usefulnot only in the field of food products but also in pharmaceuticals,cosmetics, and industrial uses.

Examples of the food composition into which the water-dispersiblecellulose, aqueous suspension-form composition, water-dispersible drycomposition and gel-forming composition of the present invention can beblended include but are not limited to, the following:

-   -   luxury drinks, such as coffee, black tea, powdered green tea,        cocoa, adzuki-bean soup, juice, soya-bean juice, etc.;    -   milk component-containing drinks, such as raw milk, processed        milk, lactic acid beverages, etc.;    -   a variety of drinks including nutrition-enriched drinks, such as        calcium-fortified drinks and the like and dietary        fiber-containing drinks, etc.;    -   dairy products, such as butter, cheese, yogurt, coffee whitener,        whipping cream, custard cream, custard pudding, etc.;    -   iced products such as ice cream, soft cream, lacto-ice, ice        milk, sherbet, frozen yogurt, etc.;    -   processed fat food products, such as mayonnaise, margarine,        spread, shortening, etc.;    -   soups;    -   stews;    -   seasonings such as sauce, TARE, (seasoning sauce), dressings,        etc.;    -   a variety of paste condiments represented by kneaded mustard;    -   a variety of fillings typified by jam and flour paste;    -   a variety or gel or paste-like food products including red        bean-jam, jelly, and foods for swallowing impaired people;    -   food products containing cereals as the main component, such as        bread, noodles, pasta, pizza pie, corn flake, etc.;    -   Japanese and European cakes, such as candy, cookie, biscuit, hot        cake, chocolate, rice cake, etc.;    -   kneaded marine products represented by a boiled fish cake, a        fish cake, etc.;    -   live-stock products represented by ham, sausage, hamburg steak,        etc.;    -   daily dishes such as cream croquette, paste for Chinese foods,        gratin, dumpling, etc.;    -   foods of delicate flavor, such as salted fish guts, a vegetable        pickled in sake lee, etc.;    -   liquid diets such as tube feeding liquid food, etc.;    -   supplements; and    -   pet foods, etc.        These food products are all encompassed within the present        invention, regardless of any difference in their forms and        processing operation at the time of preparation, as seen in        retort foods, frozen foods, microwave foods, etc.

At present, the main cellulose products compounded into food aremicrocrystalline cellulose (complex). When agitated in water, amicrocrystalline cellulose complex generates fine particles of colloidalcrystalline cellulose, and it is usually compounded into foods in thisform. The colloidal microcrystalline cellulose particles exhibit theirfunctions, such as suspension stabilizing effect and emulsionstabilizing effect, through particle-particle repulsion derived from thenegative charge on the particle surface and the three-dimensionalnetwork structure originated from the rod-like form of the particles.However, since its constitutional unit is a particle, the charge on theparticle surface is neutralized to lower the suspension stability at alow pH value. In addition, formation of the network structure requires acertain amount of the cellulose.

Contrariwise, the water-dispersible cellulose of the present inventionhas a very fine fibrous shape, unlike the colloidal microcrystallinecellulose particle. It exists in water in a relatively straight formwithout bending or rounding. Thus, it has a large exclusion volume. Thissteric hindrance is considered to be a cause of the functions, such asthickening, shape-retention, suspension stabilization, emulsionstabilization, heat stabilization, etc. Therefore, these functions areexhibited with an extremely low amount of the cellulose, and viscosityand suspension stability are not significantly affected even in anenvironment of low pH value or high ionic concentration. Although theamount of the water-dispersible cellulose (or aqueous suspension-formcomposition or water-dispersible dry composition) to be compounded intofood composition varies with the purpose of the compounding, it is, forexample, about 1-5% by weight in the case of low calorie paste, about0.05-2% by weight in fat spread, 0.01-1% by weight in ices, about0.1-0.5% by weight in mayonnaise type dressing, about 0.1-0.5% by weightin sauce or liquid dressing, and about 0.0005-0.1% by weight in drinks.

When compounded into a food composition, the water-dispersible celluloseof the present invention may be compounded together with other powderymaterials and processed according to known methods. In a more preferablemethod, the product of the present invention is formed into an aqueousdispersion having a concentration of about 0.25-2% by weight eithersingly or in combination with other ingredients, and thereaftercompounded into a food composition. In a further preferable embodiment,the dispersion into water is carried out at a temperature of 60-80° C.by the use of a high speed rotational homogenizer, a piston typehomogenizer or a cutter mixer.

Into drinks such as coffee and tea, milk components such as milk, cream,total fat powder milk, skim milk powder, or the like are oftencompounded for the purpose of giving a soft taste, enriching thenutrients and giving a milky taste. Sometimes, however, emulsificationof the milk components (fat globules) deteriorates due to a long-termstorage or heating, and the fat components float on the upper surface ofthe drink and therein gather in a ring at the point of contact betweenthe drink and a container. If such a phenomenon progresses, the wholeupper surface is covered by a white film. Though such a film istemporarily broken by shaking the drink, the thin film is immediatelyreform when the drink is allowed to stand. In an extreme case, fat isdeposited on the inner wall of container to form a ring, or the ring isbroken and mixed into the drink. Such a drink no longer has anycommercial value, and results in claims by the user. This is a problemcalled “oil-off” or “oil ring”. Further, if the emulsion is broken, themilk protein is coagulated and sometimes precipitates to the bottom ofthe container. This similarly degrades the appearance and taste. Inrecent years, not only cans but also transparent containers, such asbottles and PET bottles, are largely used. In addition, even hot drinksare now sold in the PET bottles. Thus the development of an effectivetechnique for stabilization is desired.

When compounded into a milk component containing drink, the product ofthe present invention effectively solves the problems mentioned above.As referred to in the present invention, the term “milk component” meansliquid milk (raw milk, cow milk, etc.), powdered milk (whole powderedmilk, skim milk powder, etc.), condensed milk (sugarless condensed milk,sugar-added condensed milk, etc.), cream (cream, whipping cream, etc.),yogurt, and the like. The content of the milk component in the drink isabout 0.1-12% as defatted milk solid component, and about 0.01-6% asmilk fat component. The amount of compounding is appropriately selectedin accordance with the drink of interest (for example, milk drink,milk-containing refreshing drink, etc.).

As used in the present invention, the term “milk component-containingdrink” concretely means processed milk, fermented milk drink, souredmilk drink, milk-containing teas (black tea, powdery green tea, greentea, barley water, Oolong tea, etc.), milk-containing juices (fruitjuice-containing drinks, vegetable juice-containing drinks, etc),milk-containing coffee, milk-containing cocoa, nutrients-balanced drink,liquid foods, etc. As raw materials thereof, a water-dispersiblecellulose (or aqueous suspension-form composition or water-dispersibledry composition), a milk component, main components of the drink andwater and, in addition, sweetening agent, flavour, food color, souringagent, spice, and emulsifier (glycerin fatty acid ester-monoglyceride,glycerin fatty acid ester organic acid monoglyceride, polyglycerin fattyacid ester, polyglycerin condensed ricinoleic acid ester, sorbitan fattyacid ester, propylene glycol fatty acid ester, sucrose fatty acid ester,lecithin, resolecithin, calcium stearoyllactic acid, etc.) can bereferred to. The fatty acid constituting the fatty acid ester is asaturated or unsaturated fatty acid having 6-22 carbon atoms, such ascaprylic acid, capric acid, lauric acid, myristic acid, palmitic acid,stearic acid, arachidic acid, behenic acid, oleic acid, linoleic acid,linolenic acid, arachidonic acid, erucic acid and the like. The organicacid constituting the organic acid monoglyceride are acetic acid, lacticacid, citric acid, succinic acid, diacetyltartaric acid and the like).Further, casein sodium; thickening stabilizer (κ-carrageenan,ι-carrageenan, λ-carrageenan, sodium carboxymethyl cellulose, propyleneglycol alginate, Locust bean gum, guar gum, tara gum, pectin etc.),microcrystalline cellulose, dietary fiber (indigestible dextrin,polydextrose, enzymatically hydrolyzed guar gum, water-soluble soybeanpolysaccharide, etc.), nutrient intensifier (vitamins, calcium, etc.),flavoring material (coffee powder, milk flavor, brandy, etc.), foodmaterial (sarcocarp, fruit juice, vegetables, vegetable juice, starch,cereals, soybean juice, honey, plant oils and fats, animal fats andoils, etc.), and condiments (miso, soy sauce, edible salt, sodiumglutamate, etc.) may be compounded.

A milk component-containing drink is produced according to knownmethods. For example, a powdery starting material (sugar, skim milkpowder, etc.) is added to hot water and agitated and dissolved(dispersed). Then, a liquid starting material such as coffee extract,fruit juice, cream and the like, is added and homogenized, and pouredinto a container to obtain a product. Sterilization is carried out byappropriately selecting a method of HTST (High Temperature Short Time)sterilization, hot pack sterilization, retort sterilization, etc., inaccordance with the form of article (can, bottle, PET bottle, paperpack, cup, etc.), desired storage conditions (chilled, ambienttemperature, elevated temperature, etc.) and desired storage period.Preferably, the drink of the present invention is subjected to ahomogenizing treatment at least once, after compounding all theingredients including the water-dispersible cellulose or aqueoussuspension-form composition or water-dispersible dry composition,whereby the milk component can be highly stabilized.

The water-dispersible dry composition may be compounded together withthe powdery starting material. However, the water-dispersible drycomposition can exhibit its effect only when it exists in a drink in theform of dispersed fine-fibrous cellulose, and therefore it is desirableto agitate it with a powerful agitator, such as a high speed rotationalhomogenizer, etc. Otherwise, it is also permissible to agitate awater-dispersible dry composition together with water or hot water toprepare a dispersion, before compounding. To adjust the temperature to60-80° C. and to use a piston type high pressure homogenizer (10 MPa orabove) upon preparing the dispersion is one of the preferableembodiments.

The water-dispersible cellulose (or aqueous suspension-form compositionor water-dispersible dry composition) is compounded into a milkcomponent-containing drink in an amount of about 0.001-0.5% (solid),preferably 0.005-0.2%, and more preferably 0.007-0.1%. If its amount istoo small, the oil-off preventing effect cannot be exhibitedsufficiently. If its amount is too large, the viscosity of the systembecomes too high, and the natural mouth feel (throat-passing feel) ofthe drink is adversely affected reducing its commercial value. Althoughthe detailed mechanism of the oil-off phenomenon is unknown, it isprobably due to the fact that the fat globules from the milk componentcollide with each other due to the thermal vibration to break theemulsion state, resulting in floating of the fat component and theprecipitation of protein. It is thought that, when the product of thepresent invention is used, the fine-fibrous cellulose forms a networkthroughout the whole drink, and the network produces steric hindrancewhich prevents collisions among the fat globules and prevents thedestruction of the emulsion. There is also a possibility that, sincecellulose tends to have a weak interaction with the milk components (fatglobule), the fat globules are bound to the neighborhood of thefine-fibrous cellulose and, thus, the thermal vibration of fat globulesis suppressed.

In the case of a milk coffee drink, the desirable amount of compoundingis about 0.008-0.08%. In the case of prior cellulosic additives, such asmicrocrystalline cellulose, the oil-off can be suppressed by combineduse with glycerin fatty acid ester. However, if the product is stored ata high temperature of about 60° C., the milk component and themicrocrystalline cellulose interact with each other in some cases tocause a coagulation. Contrariwise, in the case of the drinks of thepresent invention, a uniform appearance can be retained without oil-offand oil-ring and further without precipitation of protein andcoagulation or separation of the system, under conditions of chilledstorage (5° C.), ambient temperature storage (25° C.) and even hotstorage (60° C.), even if the amount of the product of the presentinvention is as small as 0.08% or less. Needless to say, it ispermissible to compound the product of the present invention with othersubstances, the effect of which has been recognized, such as anemulsifier, carrageenan, casein sodium, sodium carboxymethyl cellulose,microcrystalline cellulose, etc. In this manner, it becomes possible tosell, for example, a milk coffee in PET bottles stored hot, withoutchange in appearance, such as oil-off.

It has been known that a high concentration aqueous dispersion ofmicrocrystalline cellulose or fine-fibrous cellulose can form a gel.This type of gel is called a “weak gel”. When a slight stress is appliedto this gel, it does not flow but behaves as an elastic body. When alarge stress is applied thereto, however, it flows. Further, when thestress is eliminated, it exhibits the original nature of a weak gel.Although this type of gel exhibits softness and fluidity likemayonnaise, there is neither shape-retention such as jelly or puddingnor mouth fell in that.

On the other hand, when the gel-forming composition of the presentinvention is made into an aqueous dispersion and allowed to stand, itforms a so-called “true gel” similar to jelly and pudding. The true gelis different from the weak gel in that the true gel does not flow but isstructurally broken when an excessive stress is applied thereto. When atrue gel is ground, it assumes the state of a microgel which is anassembly of small gels. The microgel is a sort of weak gel.

There have hitherto been many techniques known for forming a gel by acombined use of a plurality of polysaccharides. For example, thecombination of xanthane gum and Locust bean gum and the combination ofcarrageenan and Locust bean gum are included. As a true gel constitutedof cellulose and other polysaccharides, JP-A-63-196238 discloses that agel material can be obtained by mixing a microfibrillated cellulose withkonjac taro or konjac powder to prepare a slurry and then drying theslurry or freezing and melting it. However, this gel becomes very rigidas does gummy candy when dried, and when frozen and melted, this gelundergoes a marked separation of water to give an uneven texture toostrong to bite off. The gel was thus not applicable to food products.

As used in the present invention, alginic acids inclusively meansalginic acid, salts thereof and propyleneglycol alginate. Since thesematerials have to be used in the state of being dissolved in water, pHcontrol and salt concentration control may be necessary. Sodium alginateis especially preferable because of its water-solubility. Alginic acidis a 1,4-bonding type block copolymer consisting of β-D-mannuronic acid(abbreviated to M) and α-L-glucuronic acid (abbreviated to G). Analginic acid molecule is constituted of three segments, i.e. a blockconsisting of M (M-M-M-M), a block consisting of G (G-G-G-G), and ablock consisting of alternative combination of both residues (M-G-M-G).On the other hand, galactomannan has in its structure a main chainconsisting of β-1,4-bonded β-D mannose residues and side chainsconsisting of α-1,6-bonded α-D-galactose residues. There are variousgalactomannans, such as guar gum, tara gum, Locust bean gum, etc. whichare different from one another in the proportions of mannose andgalactose. Since many of the galactomannans have unique odor originatedfrom the starting material, the use of odorless purified product ispreferable. Glucomannan has a structure of β-1,4-bonded D-glucose andD-mannose, wherein the ratio of glucose to mannose is about 2:3. Konjacpowder and alcohol-purified glucomannan are included, among whichpurified glucomannan of high degree of polymerization is preferable.Concretely saying, those having a viscosity of 30 Pa·s or above at 25°C., when made into a 1% aqueous solution, are preferable, and thosehaving a viscosity of 40 Pa·s or above are especially preferable.

As mentioned above, a gel composition is formed when a water-dispersibledry composition and at least one polysaccharide selected from alginicacids, galactomannan and glucomannan are dispersed in water and thenleft to stand. However, formation of the gel composition is not limitedto the case where the water-dispersible dry composition is used. Thewater-dispersible cellulose or the aqueous suspension-form compositioncan also be used. However, the highest gel strength is attained when thewater-dispersible dry composition can also be used. As for the amount tobe compounded, the water-dispersible dry composition (orwater-dispersible cellulose or aqueous suspension-like composition) isused in an amount of 0.15% (solid) or more, and at least onepolysaccharide selected from alginic acids, galactomannan andglucomannan is used in an amount of 0.03% or more. The total solidcomponent concentration has an upper limit of about 5%. Gel strength(breaking strength) of the gel composition prepared is at most about 1N.The polysaccharide may be added in the form of a powder, or mixed with awater-dispersible dry composition (or water-dispersible cellulose oraqueous suspension-form composition) dispersed in water, after it ismade into an aqueous solution (swollen solution). If the polysaccharideis used after making it into an aqueous solution (or swollen solution),the gel-strength is apt to become high. If it is mixed at a hightemperature (above 30° C.), gel-formation begins immediately, andtherefore a higher gel strength can be obtained by carrying out themixing at a lower temperature (for example, about 5° C.) with a highspeed agitation, in a short period of time.

If these gel-form compositions are subjected to a heat treatment, ahigher gel-strength (breaking strength) can be attained. The term “heattreatment” means an operation of maintaining a state of standing at atemperature of 30° C. or above. The heat treatment may be carried outeither at the time of forming the gel-form composition by leaving themixture obtained by mixing the water-dispersible dry composition (orwater-dispersible cellulose or aqueous suspension-form composition) witha polysaccharide to stand, or after the formation of gel composition.

A higher temperature of heat treatment can give a higher gel strength ina shorter period of time. When the gel-form composition is heated afterit is once formed, the gel strength will markedly increase by theheating for a period of several seconds to several days at a temperaturehigher than that used to form the gel composition, such as 60-120° C. orat a higher temperature. The strength is maintained even if thetemperature is reduced to a lower temperature. That is, it is thermallyirreversible. This gel composition does not dissolve or cause separationof water even if it is re-heated, and, thus, has a very high heatstability. Accordingly, the gel composition can be warmed before beingeaten. Concretely saying, the composition can maintain its gel strengthof 0.01-1N at 50° C. or above. If the amount of the gel composition isreduced, it gives a very soft gel similar to the existing gels, but itis still excellent in heat stability and shows no separation of water.Accordingly, it is most suitable for use as a general desert and as aretort food such as a food for people with swallowing disorders, whichfood has attracted public interest in recent years. This is, from theviewpoint of diversification of meals, due to the facts that a warm mealcan be offered, that the extent of water separation is small even if thegel is soft, and that the gel structure can be maintained even in thecase of retort sterilization so that solid components such as choppedfood or the like, if it is compounded, do not precipitate. This makes itpossible to maintain the same uniform state of the food as the onebefore the sterilization. Since the gel composition is not dissolved ordisintegrated even when thrown into hot water, the composition can be indiced form and used as an ingredient in miso soup or other soups.

As the compounded components in the gel-forming composition and gelcomposition, those composed of the water-dispersible cellulose andsodium carboxymethyl cellulose are most suitable. When galactomannan isused as the polysaccharide, the gel-strength is apt to become high evenat low temperatures. However, attention should be paid to the fact that,if heated excessively, the galactomannan is decomposed and the gelstrength becomes low. Since glucomannan is high in heat stability, itsgel strength scarcely decrease even if heated after formation of the gelcomposition. Since high-viscosity type glucomannan, it is preferable touse glucomannan by previously making it into a swollen solution.Although there are respective optimum compounding ratios between thewater-dispersible dry composition (or water-dispersible cellulose oraqueous suspension-form composition) and polysaccharide, the optimumratio is about 5-40% by weight as expressed in terms of proportion ofpolysaccharide. For example, in the case of Locust bean gum, theproportion is about 50% by weight, in the case of tara gum, it is about10% by weight, and in the case of glucomannan, it is about 30% byweight.

As used herein, the term “gel composition having a sponge-likestructure” (hereinafter, referred to as “sponge-like gel”) means a gelhaving a sponge-like texture. The pores therein have a minor axis (d)and a major axis (l) of about 1-1,000 μm, and d/l of about 1-10, with apolygonal shape, such as triangle, square, trapezoid, rhomb, pentagon,hexagon, etc. The shape of the pores can be observed with a gel cut intoa thin section by a sharp knife, by observing it under an opticalmicroscope with transmitting light or polarized light, in the presenceof a sufficient quantity of water. It is also possible to observe theshape of the pores by SEM after freeze-drying. In the partition wallsdefining the pores, the water-dispersible cellulose and glucomannan forma gel, and the water content therein is about 5-50%. The quantity ofwater retained in the pores is about 90-95%.

The sponge-like gel of the present invention includes awater-dispersible dry composition (or water-dispersible cellulose oraqueous suspension-form composition), glucomannan and water. Theapproximate composition (solid) is a water-dispersible dry composition(or water-dispersible cellulose or aqueous suspension-form composition):glucomannan=85:15 to 35:65 (solid), and preferably 80:20 to 37:63 andparticularly preferably 75:25 to 40:60. When the composition ratio is inthe above-mentioned range, a higher breaking strength is exhibited. Thetotal solid concentration in the gel is about 0.1-5%, and particularlypreferably 0.5-1.5%. If the solid concentration is low, the gel strength(breaking strength) becomes low. When the concentration is too high theviscosity of the system becomes too high and agitation and mixing becomedifficult to carry out.

The sponge-like gel of the present invention is edible, and usable infood products. It has a hardness which is low enough for a healthyperson to bite off and chew. The gel strength (breaking strength)thereof is about 0.1-5N. Similar to a sponge used for washing tableware,the sponge-like gel of the present invention releases water withshrinkage of its volume, when pushed with spoon or the like. When asufficient amount of water is added thereto, the sponge absorbs thewater and swells until it recovers the original shape. This operationcan be repeated and, thus, absorption and separation of water can bepracticed reversibly. Even so, as mentioned above, the sponge-like gelhas a hardness sufficiently low that one can bite off and chew it. Ithas a crunchy or crispy texture, which comes from the sponge texture.The mouth feel exhibited by this gel when eaten, namely the juicy feelbrought about by the water exuding from the whole gel and the crunchymouth feel upon biting it off, is a novel mouth feel different from thatof the existing gels, such as agar, carrageenan/Locust bean gum gel,nata-de-coco, konjac, etc.

For preparing the sponge-like gel of the present invention, it is firstnecessary to bring the water-dispersible dry composition (orwater-dispersible cellulose or aqueous suspension-form composition) intoa state where fine-fibrous cellulose is uniformly dispersed in water.For this purpose, it is desirable to make a dispersion with a powerfulapparatus, such as a high speed rotational homogenizer, a piston typehigh pressure homogenizer or the like. More preferably, the temperatureat the time of making the dispersion is 60° C. or higher. For dissolving(swelling) a high viscosity type glucomannan in water, a known methodmay be used. For example, glucomannan may be added to water at roomtemperature and stirred, after which the mixture is allowed to stand for7 hours or more. The water-dispersed mixture may be prepared by firstdispersing a water-dispersible dry composition (or water-dispersiblecellulose or aqueous suspension-form composition) in water and thenadding glucomannan powder and thoroughly agitating the mixture, or byadding aqueous solution of glucomannan and then stirring and mixing theresulting mixture. Examples of the high speed rotational homogenizerinclude TK Homomixer manufactured by Tokushu Kika Kogyo, Co., Ltd.,Excel Autohomogenizer manufactured by Nippon Seiki, Co., Ltd. and thelike.

Subsequently, this water-dispersed mixed solution is frozen. This stepmay be carried out by agitating and mixing the solution, allowing it tostand to form a gel composition and thereafter freezing the resultingcomposition, or by immediately freezing the prepared mixture. A highergel strength (breaking strength) of the sponge-like gel can be attainedby once forming a gel composition with high gel strength (breakingstrength) by a heat treatment or the like and thereafter carrying outthe freezing.

The freezing is carried out by introducing a water-dispersed mixedsolution into a container and cooling it to a temperature lower than thefreezing point. The methods include a method of dipping in a coolingmedium such as brine or the like; a method of standing in a lowtemperature atmosphere, such as in a refrigerator, a method of coolingto a temperature lower than freezing point under an elevated pressureand thereafter reducing the pressure to atmospheric pressure to promotefreezing, etc. One of these methods may be selected appropriately. Thefreezing temperature (freeing velocity) drastically influences theformation of the sponge-like texture. For example, when freezing isslowly carried out at a relatively high temperature not lower than −20°C., large pores and thick partition walls are formed and the resultingmouth feel tends to become highly crunchy. On the other hand, when thefreezing is carried out rapidly at a relatively low temperature of −45°C. or lower, small pores are formed and the resulting mouth feel tendsto become soft and smooth. This is probably attributable to the factthat the pores in the sponge-like structure are dependent on the growthof ice crystals. The de-freezing is carried out by allowing the frozenproduct to stand at a temperature exceeding 0° C. For example, thethawing temperature may be room temperature or a higher temperature

Into the sponge-like gel of the present invention, other food materials,such as starches, oils and fats, proteins, salts and the like andseasoning, sweetening agents, food colors, spices, souring agents,emulsifiers, thickening stabilizers, dietary fibers, nutrientintensifiers (vitamins, calcium, etc.) and flavor materials may becompounded, for the purpose of improving flavor and appearance, so longas addition of these materials does not adversely affect gelformability.

The sponge-like gel of the present invention is suitably usable in theingredients of desert, such as fruit punch, anmitsu (boiled peas withhoney and bean jam), jelly and the like. In this case, for example, asponge-like gel is formed from a water-dispersible dry composition (orwater-dispersible cellulose or aqueous suspension-form composition),glucomannan and water and thereafter the gel is dipped in syrup andmixed into a desert.

Further, the gel of the present invention is suitable for use inaccentuation of drinks, soups, fillings, etc. The property of theproduct of the present invention of reversibly absorbing and releasingwater, may be useful in the fields of pharmaceuticals, cosmetics, andindustrial products, too.

EXAMPLES

Hereinbelow, the present invention will be described in further detailsby way of the examples. The measurements mentioned in the examples werecarried out in the following manner.

<Average Degree of Polymerization of Cellulosic Substance>

The average degree of polymerization of cellulosic substance isdetermined according to ASTM Designation: D 1795-90 “Standard TestMethod for Intrinsic Viscosity of Cellulose”.

<α-Cellulose Content of Cellulosic Substance>

This determination is carried out according to JIS P8101-1976 “Methodfor Testing Dissolved Pulp” 5.5 α-Cellulose.

<Shape (Major Axis, Minor Axis, Major Axis/Minor Axis Ratio) ofCellulose Fiber (Particle)>

Since the sizes of cellulose fiber (particle) vary in a wide range, itis impossible to observe all the cases with only one kind of microscope.Accordingly, an optical microscope and a scanning microscope (mediumresolution SEM and high resolution SEM) are appropriately selectedaccording to the size of fiber (particle) to carry out observation andmeasurement.

When an optical microscope is used, an aqueous dispersion of cellulosefiber (particle) adjusted to an appropriate concentration is put on aslide glass, covered with a cover glass, and observed.

When a medium resolution SEM (JSM-5510LV, manufactured by JEOL Ltd.) isused, an aqueous sample solution is put on a sample stand and air dried,after which about 3 nm of Pt—Pd is vapor-deposited thereon and thesample is then observed.

When a high resolution SEM (S-5000, manufactured by Hitachi ScienceSystems, Co., Ltd.) is used, a sample aqueous dispersion is put on asample stand and air-dried, and then about 1.5 nm of Pt—Pd isvapor-deposited and the sample is then observed.

A major axis, a minor axis and a major axis/minor axis ratio of acellulose fiber (particle) was measured on 15 or more particles selectedfrom the photographs. In the examples mentioned below, the shapes of thefibers ranged from nearly straight ones to curved ones (like hair), butnone of them was in curled form like waste yarn. The minor axis(thickness) varied in a wide range within one thread of fiber, and thusan average value was taken. The high resolution SEM was used forobservation of fibers having a minor axis of about several nm to 200 nm,but one thread of fiber was too long and could not be observed in asingle visual field. Thus, photographing was repeated while moving thevisual field, after which the photographs were combined and analyzed.

<Loss Tangent> (=Loss Elastic Modulus/Storage Elastic Modulus)

-   (1) A sample and water were weighed out so as to give an aqueous    dispersion having a solid concentration of 0.5% by weight, and    dispersed with Ace Homogenizer (manufactured by Nippon Seiki, Co.,    Ltd., model AM-T) at 15,000 rpm for 15 minutes.-   (2) The dispersion was left standing in an atmosphere of 25° C. for    3 hours.-   (3) The sample solution was introduced into a dynamic    viscoelasticity measuring apparatus and left standing for 5 minutes,    before measurement under the following conditions. From the results    thereof, a loss tangent (tan δ) at a frequency of 10 rad/s was    determined.    -   Apparatus: ARES (Model 100 FRTN1) (manufactured by Rheometric        Scientific Inc.)    -   Geometry: Double Wall Couette    -   Temperature: 25° C.    -   Strain: 10% (fixed)    -   Frequency: 1 to 100 rad/s (elevated over a period of about 170        seconds)<        <0.25% Viscosity>-   (1) A sample and water were weighed out so as to give an aqueous    dispersion having a solids concentration of 0.25% by weight, and    dispersed at 15,000 rpm for 15 minutes with Ace Homogenizer (Model    AM-T, manufactured by Nippon Seiki, Co., Ltd.).-   (2) The dispersion was left standing at 25° C. for 3 hours.-   (3) After thorough stirring, a rotational viscometer (B type    viscometer BL form, manufactured by Tokimek, Co., Ltd.) was set up.    Thirty seconds after completing the stirring, rotation of the rotor    was started. Thirty seconds thereafter, the indication of the    viscometer was read, from which viscosity was calculated. The speed    of rotation of the rotor was fixed at 60 rpm, and the rotor was    altered appropriately, depending on the viscosity.    <Sedimentation Volume>-   (1) A sample and water were weighed out so as to give an aqueous    dispersion of 0.5% by weight, and were introduced into a glass    container equipped with a lid. The contents were shaken and stirred    by hand about 20 times.-   (2) 100 mL of the sample solution was poured into a glass tube    having an inner diameter of 25 mm, and the tube was turned    upside-down several times to stir the contents, after which the tube    was left to stand at ambient temperature for 4 hours.-   (3) The volume of the turbid (or semi-transparent) suspension layer    was visually observed, which was taken as the sedimentation volume    (%).    <Content of “Component Stably Suspensible in Water” in    Water-Dispersible Cellulose>

(1) A sample and water were weighed out so as to give an aqueousdispersion with a cellulose concentration of 0.1% by weight, anddispersed with Ace Homogenizer (Model AM-T, manufactured by NipponSeiki, Co., Ltd.) at 15,000 rpm for 15 minutes.

(2) 20 g of the sample solution was introduced into a centrifugal tubeand centrifuged with a centrifugal machine at 1,000 G for 5 minutes.

(3) The upper liquid layer was removed, and the weight of the sedimentedcomponent (a) was measured.

(4) Then, the sedimented component was absolutely dried, and weight ofthe solid component (b) was measured.

(5) According to the following formula, the content of “component stablysuspensible in water” (c) was calculated:c=5,000×(k1+k2) [% by weight]

Provided that, when the system contained no water-soluble polymer(and/or hydrophilic substance), k1 and k2 were calculated according tothe following formulae:k1=0.02−bk2={k1×(a−b)}/(19.98−a+b)

When the system contained a water-soluble polymer (and/or a hydrophilicsubstance), k1 and k2 were calculated according to the followingformulae:k1=0.02−b+s2k2=k1×w2/w1cellulose/water-soluble polymer(hydrophilic substance)=f/d[compoundingratio]w1=19.98−a+b−0.02×d/fw2=a−bs2=0.02×d×w2/{f×(w1+w2)}

When the content of the “component stably dispersible in water” was verylarge, the weight of sedimented component became small, and thereforethe accuracy of measurement would be low so far as the above-mentionedmethod is used. In such cases, therefore, the procedures of (3) andthereafter were carried out in the following manner.

(3′) The upper liquid layer was taken out and the weight thereof (a′)was measured.

(4′) Then, the upper layer component was absolutely dried and the weightof solid component (b′) was measured.

(5′) According to the following formula, the content of the “componentstably dispersible in water” (c) was calculated:c=5,000×(k1+k2) (% by weight)

Provided that, when the system contained no water-soluble polymer(and/or hydrophilic substance), k1 and k2 were calculated according thefollowing formulae:k1=b′k2=k1×(19.98−a′+b′)/(a′−b′)

When the system contained a water-soluble polymer (and/or a hydrophilicsubstance), k1 and k2 were calculated according to the followingformulae:k1=b′−s2×w1/w2k2=k1×w2/w1

-   -   cellulose/water-soluble polymer (hydrophilic        substance)=f/d(compounding ratio)        w1=a′−b′        w2=19.98−a′+b′−0.02×d/f        s2=0.02×d×w2/{f×(w1+w2)}

When, in the operation of (3), the boundary between the upper liquidlayer and the sedimented component was not clear and the separation wasdifficult, the operation was carried out at an appropriately loweredconcentration of cellulose.

Example 1

Commercially available wood pulp (average degree ofpolymerization=1,710, α-cellulose content=93% by weight) was cut into6×12 mm rectangles and dipped into a sufficient amount of water.Immediately hereafter, the pulp was withdrawn from the water, and thewater was swished off in a sieve. At that time, water content was 74% byweight. When the wet pulp was passed once through a cutter mill(“Comitrol” Model 1700, manufactured by URSCHEL LABORATORIES, Inc.,microcut head/blade distance: 2.029 mm, impeller rotation speed: 9,000rpm), the fiber length became 0.25-3.25 mm (content of the componentwith fiber length of 0.5 mm or more was about 98%).

The cutter mill-treated product and water were weighed out so as to givea fiber content of 2% by weight, and the mixture was agitated until noentanglement between fibers was observed. The aqueous dispersion thusobtained was treated with a whetstone-rotation type pulverizer(“Cerendipiter” Model MKCA6-3, manufactured by Masukou Sangyo, Co.,Ltd.; grinder: MKE6-46, grinder rotation speed: 1,800 rpm). The numberof the treatments was four and the grinder clearance was changed to200→60→40→40 μm, respectively. The aqueous dispersion thus obtained hada sedimentation volume of 93%.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to make the concentration 1% by weight, and the diluted dispersionwas passed eight times through a high pressure homogenizer(“Microfluidizer” Model M-110Y, manufactured by MFIC Corp., treatmentpressure: 110 MPa). Then, the dispersion was centrifuged at 35,000 G for30 minutes, the supernatant liquid was discarded, and the sediment wasdehydrated between filter papers to obtain water-dispersible cellulose Ahaving a water content of 82% by weight. A 0.25% viscosity thereof was70 mPa·s. Crystallinity thereof was 82%. When it was observed with aoptical microscope and a medium-resolution SEM, fine fibrous cellulosehaving a major axis of 10-400 μm, a minor axis of 1-10 μm and a majoraxis/minor axis ratio of 10-300 was observed. The loss tangent was 0.21.Although it was attempted to measure the water retention thereofaccording to JAPAN TAPPI Paper Pulp Testing Method No. 26, the wholesample passed through a cup filter, and the value could not bedetermined. The content of “component stably dispersible in water” was95% by weight. When the component was observed with a high resolutionSEM, very fine fibrous cellulose having a major axis of 0.9-20 μm, aminor axis of 5-100 nm and a major axis/minor axis ratio of 30-300 wasobserved.

Example 2

Commercially available wheat straw pulp (average degree ofpolymerization=930, α-cellulose content=68% by weight) was cut into 6×12mm rectangles. Water was added thereto so as to give a concentration of4% by weight. The mixture was agitated with a domestic mixer for 5minutes. When the mixture was dispersed with a high speed rotationalhomogenizer (ULTRA-DISPERSER, Model LK-U, manufactured by Yamato Kagaku)for one hour, the fiber length became 4 mm or less.

The aqueous dispersion thus obtained was twice treated with awhetstone-rotation type pulverizer (“Cerendipiter” Model MKCA6-3,grinder: MKE6-46, grinder rotation number: 1,800 rpm), while alteringthe grinder clearance as 60→40 μm, respectively. The aqueous dispersionthus obtained had a sedimentation volume of 95% by volume.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to a concentration of 1% by weight, and the diluted dispersion waspassed through a high pressure homogenizer twenty times(“Microfluidizer” Model M-110Y, treatment pressure 110 MPa) to obtain anaqueous suspension-form composition B. Crystallinity thereof was 72%. A0.25% viscosity was 84 mPa·s. When it was observed by means of anoptical microscope and a medium-resolution SEM, fine-fibrous cellulosehaving a major axis of 10-900 μm, a minor axis of 1-30 μm and a majoraxis/minor axis ratio of 6-100 was observed. The loss tangent was 0.19.Although it was attempted to measure the water retention thereof, thewhole sample passed through a cup filter and the value could not bedetermined. The content of the “component stably dispersible in water”was 99% by weight. When the component was observed by means of a highresolution SEM, very fine fibrous cellulose having a major axis of0.7-15 μm, a minor axis of 4-200 nm and a major axis/minor axis ratio of30-350 was observed.

Example 3

The product from the whetstone rotation type pulverizer treatment inExample 2 was diluted with water to a concentration of 2% by weight, andpassed through a high pressure homogenizer eight times (“UltimizerSystem “Model HJP25030, manufactured by Sugino Machine, Co., Ltd.,treatment pressure: 175 MPa) to obtain an aqueous suspension-formcomposition C. A crystallinity was 74%. A 0.25% viscosity was 69 mPa·s.When it was observed by means of an optical microscope, fine fibrouscellulose having a major axis of 10-700 μm, a minor axis of 1-30 μm anda major axis/minor axis ratio of 10-150 was observed. A loss tangent was0.43. Although it was attempted to measure water retention thereof, thewhole sample passed through a cup filter and the value could not bedetermined. The content of the “component stably dispersible in water”was 89% by weight. When the component was observed by means of a highresolution SEM, very fine fibrous cellulose having a major axis of 1-20μm, a minor axis of 6-300 nm and a major axis/minor axis ratio of 30-350was observed.

Example 4

Commercially available rice straw pulp (average degree ofpolymerization=810, α-cellulose content=82% by weight, water content=55%by weight) was thrown into water while tearing it by hand, and agitateduntil no entanglement between fibers was observed. Thus, an aqueousdispersion having a solid concentration of 3% by weight was prepared.The fiber length was 2.5 mm or less.

The aqueous dispersion thus obtained was twice treated with awhetstone-rotation type pulverizer (“Cerendipiter” Model MKCA6-3,grinder rotation number: 1,800 rpm). In the first passage, the grinderused was MKE6-46 and clearance was 100 μm, and in the second passage,the grinder was MKGAW6-80 and clearance was 50 μm. The aqueousdispersion thus obtained had a sedimentation volume of 83% by volume.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to make the concentration 0.5% by weight, and the diluteddispersion was passed through a high pressure homogenizer six times(“Microfluidizer” Model M-140K, treatment pressure: 175 MPa) to obtainan aqueous suspension-form composition D. The crystallinity thereof was65%. A 0.25% viscosity was 43 mPa·s. When it was observed by means of anoptical microscope, fine fibrous cellulose having a major axis of 30-800μm, a minor axis of 1-40 μm and a major axis/minor axis ratio of 8-120was observed. A loss tangent was 0.91. Although it was attempted tomeasure water retention thereof, a part of the sample passed through acup filter but the remainder caused clogging, so that the value couldnot be determined. The content of the “component stably dispersible inwater” was 37% by weight. When the component was observed by means of ahigh resolution SEM, very fine fibrous cellulose having a major axis of1-20 μm, a minor axis of 10-300 nm and a major axis/minor axis ratio of25-350 was observed.

Example 5

Commercially available wood pulp (average degree ofpolymerization=1,820, α-cellulose content=77% by weight) was cut into6×16 mm rectangles and a sufficient amount of water was added thereto soas to give a solid concentration of 80% by weight. The mixture waspassed through a cutter mill (“Comitrol” Model 1700, cutting head bladedistance: 2.03 mm, impeller rotation speed: 3,600 rpm), with controllingthe separation of the water and the pulp chip to a minimum. As a result,the fiber length became 0.75-3.75 mm.

The cutter mill-treated product, sodium carboxymethyl-cellulose andwater were weighed out so that the concentration of sodiumcarboxylmethyl-cellulose came to 0.0706% by weight, and the mixture wasagitated until no entanglement between fibers was observed. The aqueousdispersion thus obtained was treated with a whetstone-rotation typepulverizer (“Celendipiter” Model MKCA6-3, manufactured by MasukouSangyo, Co., Ltd.; grinder: MKE6-46, grinder rotation speed: 1,800 rpm).The treatment was carried out twice, while altering the grinderclearance as 110→80 μm, respectively. The aqueous dispersion thusobtained had a sedimentation volume of 89%.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to a concentration 0.5% by weight, and the diluted dispersion waspassed through a high pressure homogenizer eight times (8 times)(“Microfluidizer” Model M-110Y, treatment pressure: 110 MPa) to obtainan aqueous suspension-form composition E. Crystallinity thereof was 79%or more. A 0.25% viscosity thereof was 128 mPa. When it was observed bymeans of an optical microscope and a medium-resolution SEM, fine fibrouscellulose having a major axis of 30-900 μm, a minor axis of 1-50 μm anda major axis/minor axis ratio of 6-200 was observed. A loss tangent was0.45. Although it was attempted to measure water retention thereof, apart of the sample passed the cup filter but the remainder causedclogging, so that the value could not be determined. The content of the“component stably dispersible in water” was 75% by weight. When thecomponent was observed by means of a high resolution SEM, very finefibrous cellulose having a major axis of 1-20 μm, a minor axis of 8-150nm and a major axis/minor axis ratio of 30-350 was observed.

Example 6

The whetstone rotation type pulverizer-treated product of Example 5 wasdirectly passed through a high pressure homogenizer four times (4 times)(“Microfluidizer” Model 110Y, treatment pressure: 95 MPa) to obtain anaqueous suspension-form composition F. The crystallinity was 79% orhigher. A 0.25% viscosity was 68 mPa·s. When it was observed by means ofan optical microscope, fine fibrous cellulose having a major axis of10-400 μm, a minor axis of 1-5 μm and a major axis/minor axis ratio of10-300 was observed. The loss tangent was 0.64. Although it wasattempted to measure water retention thereof, a part of the samplepassed the cup filter but the remainder caused clogging, so that thevalue could not determined. The content of the “component stablydispersible in water” was 43% by weight. When the component was observedby means of a high resolution SEM, very fine fibrous cellulose having amajor axis of 1-20 μm, a minor axis of 10-150 nm and a major axis/minoraxis ratio of 30-300 was observed.

Example 7

The cutter mill-treated product of Example 5, sodiumcarboxymethyl-cellulose and water were weighed out so that theconcentration of cellulose came to 3% by weight and the concentration ofsodium carboxylmethyl-cellulose came to 0.106% by weight, and wasagitated until no entanglement between fibers was observed. The aqueousdispersion thus obtained was treated with a whetstone-rotation typepulverizer (“Cerendipiter” Model MKCA6-3, manufactured by MasukouSangyo, Co., Ltd.; grinder: MKE6-46, grinder rotation speed: 1,800 rpm).The treatment was carried out twice while altering the grinder clearanceto 150→120 μm, respectively. The aqueous dispersion thus obtained had asedimentation volume of 91%.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to make the concentration 3% by weight, and the diluted dispersionwas passed through a high pressure homogenizer five times (5 times)(“Microfluidizer” Model M-140K, treatment pressure: 200 MPa) to obtainan aqueous suspension-form composition G. Crystallinity thereof was 76%or higher. A 0.25% viscosity thereof was 67 mPa. When it was observed bymeans of an optical microscope, fine fibrous cellulose having a majoraxis of 20-700 μm, a minor axis of 1-50 μm and a major axis/minor axisratio of 5-150 was observed. The loss tangent was 0.31. Although it wasattempted to measure water retention thereof, a part of the samplepassed the cup filter but the remainder caused clogging, so that thevalue could not be determined. The content of the “component stablydispersible in water” was 59% by weight. When it was observed by meansof a high resolution SEM, very fine fibrous cellulose having a majoraxis of 1-15 μm, a minor axis of 10-80 nm and a major axis/minor axisratio of 30-300 was observed.

Example 8

Sodium carboxymethylcellulose was added to the aqueous suspension-formcomposition C (Example 3) so that the ratio of cellulose:sodiumcarboxymethylcellulose came to 85:15 (parts by weight), and agitated andmixed with an agitation type homogenizer for 15 minutes.

Subsequently, the aqueous suspension-form composition was dried by meansof a drum drier and scraped out by means of a scraper. It was pulverizedby means of a cutter mill (“Flush Mill”, manufactured by Fuji Powdal,Co., Ltd.) to such an extent that the pulverized material come to almostcompletely pass through a sieve having a mesh size of 1 mm to obtain anwater-dispersible dry composition H.

The water-dispersible dry composition H had a crystallinity of 71% orabove, a 0.25% viscosity of 61 mPa·s, and a loss tangent of 0.51. Thecontent of the “component stably suspensible in water” was 75% byweight. When the component was observed by means of a high resolutionSEM, very fine fibrous cellulose having a major axis of 1-20 μm, a minoraxis of 10-300 nm and a major axis/minor axis ratio of 30-350 wasobserved.

Example 9

Sodium carboxymethylcellulose was added to the aqueous suspension-formcomposition F (Example 6) so that the ratio of cellulose:sodiumcarboxymethylcellulose came to 80:20 (parts by weight), and agitated andmixed by an agitation type homogenizer for 15 minutes.

Subsequently, the aqueous suspension-form composition was dried by meansof a drum drier and scraped out by means of a scraper. It was pulverizedby means of a cutter mill (“Flush Mill”) to such an extent that thepulverized material became to almost completely pass through a sievehaving a mesh size of 1 mm to obtain an water-dispersible drycomposition I.

The water-dispersible dry composition I had a crystallinity of 77% orhigher, a 0.25% viscosity of 66 mPa·s, and a loss tangent of 0.65. Thecontent of the “component stably suspensible in water” was 40% byweight. When the component was observed by means of a high resolutionSEM, very fine fibrous cellulose having a major axis of 1-20 μm, a minoraxis of 10-150 nm and a major axis/minor axis ratio of 30-300 wasobserved.

Example 10

Commercially available bagasse pulp (average degree ofpolymerization=1,320, α-cellulose content=77%) was cut into 6×16 mmrectangles. Bagasse pulp, sodium carboxymethyl-cellulose and water wereweighed out so that the concentration of cellulose came to 3% by weightand the concentration of sodium carboxymethyl-cellulose came to 0.176%by weight, and the mixture was agitated by means of a domestic mixer for5 minutes.

The aqueous dispersion thus obtained was treated three times with awhetstone-rotation type pulverizer (“Cerendipiter” Model MKCA6-3,grinder: MKE6-46, grinder rotation speed: 1,800 rpm). The aqueousdispersion thus obtained had a sedimentation volume of 100 by volume.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to make the concentration 2% by weight, and the diluted dispersionwas passed through a high pressure homogenizer four times (4 times)(“Microfluidizer” Model M-140K, treatment pressure 110 MPa) to obtain anaqueous suspension-form composition. The crystallinity thereof was 73%or higher. A 0.25%. The viscosity thereof was 120 mPa·s. When it wasobserved by means of an optical microscope and a medium resolution SEM,fine fibrous cellulose having a major axis of 10-500 μm, a minor axis of1-25 μm and a major axis/minor axis ratio of 5-190 was observed. A losstangent was 0.32. The content of the “component stably dispersible inwater” was 99% by weight.

Sodium carboxymethyl-cellulose was added to the aqueous suspension-formcomposition so that the cellulose:sodium carboxymethyl-cellulose ratiocame to 85:15 (parts by weight), and the mixture was agitated and mixedby an agitation type homogenizer for 15 minutes. Subsequently, theaqueous suspension-form composition was dried by means of a drum drierand scraped out by means of a scraper. It was pulverized by means of acutter mill (“Flush Mill”, manufactured by Fuji Powdal, Co., Ltd.) tosuch an extent that the pulverized material came to almost completelypass through a sieve having a mesh size of 2 mm to obtain awater-dispersible dry composition J. The water-dispersible drycomposition J had crystallinity of 73%, a 0.25% viscosity of 143 mPa·s,and a loss tangent was 0.38. The content of the “component stablysuspensible in water” was 98% by weight. When the “component stablydispersible in water” was observed by means of a high resolution SEM,very fine fibrous cellulose having a major axis of 1-17 μm, a minor axisof 10-350 nm and a major axis/minor axis ratio of 20-250 was observed.

Example 11

Gel-forming composition K was prepared by mixing water-dispersible drycomposition H (85 parts by weight) and sodium alginate (viscosity of 1%aqueous solution thereof was 500-600 mPa·s at 20° C.) (15 parts byweight).

Subsequently, Composition K and water were weighed out so as to give asolid component concentration of 1% by weight, and dispersed by means ofAce Homogenizer (Model AM-T, manufactured by Nippon Seiki, Co., Ltd.) at15,000 rpm for 10 minutes at 25° C. The dispersion was filled into acylindrical glass vessel having an inner diameter of 45 mm up to aheight of about 45 mm and left to stand at 5° C. for 24 hours to obtaina gel composition. The gel strength at 5° C. was 0.04N.

The gel strength (breaking strength) was measured directly, withoutremoving the gel composition from the container, by means of Rheometer(“RHEO METER” Model NRM-2002J; pushing-in jig: 10 mmφspherical jig;velocity of pushing-in 2 cm/min.)<

Example 12

Gel-forming composition L was prepared by mixing water-dispersible drycomposition H (85 parts by weight) and guar gum (viscosity of 1% aqueoussolution thereof at 25° C.: 900-1,100 mPa·s) (15 parts by weight).

Subsequently, Composition L and water were weighed out so as to give asolid component concentration of 1% by weight, and dispersed by means ofAce Homogenizer at 15,000 rpm for 10 minutes at 80° C. The dispersionwas filled into a cylindrical glass vessel having an inner diameter of45 mm up to a height of about 45 mm and left to stand at 5° C. for 24hours to obtain a gel composition. The gel strength at 5° C. was 0.16N.The gel strength was measured in the same manner as in Example 11.

Example 13

Gel-forming composition M was prepared by mixing water-dispersible drycomposition H (60 parts by weight) and glucomannan (viscosity of 1%aqueous solution thereof after standing at 25° C. for 7 hours: 100 Pa·sor higher) (40 parts by weight).

Subsequently, Composition M and water were weighed out so as to give asolid component concentration of 1% by weight, and dispersed by means ofAce Homogenizer at 15,000 rpm for 10 minutes at 80° C. The dispersionwas filled into a cylindrical glass vessel having an inner diameter of45 mm up to a height of about 45 mm and left to stand at 5° C. for 24hours to obtain a gel composition. The gel strength at 5° C. was 0.32N.

When the gel composition was left to stand at 60° C. for 24 hours, itsgel strength (60° C.) became 1.6N. Neither separation of water nordeformation was observed.

When the gel composition was heat treated at 120° C. for 15 minutesimmediately after the dispersing operation, a gel composition having agel strength (25° C.) of 0.36N was obtained. The gel strengths were allmeasured in the same manner as in Example 11.

Example 14

Gel-forming composition N was prepared by mixing water-dispersible drycomposition I (60 parts by weight) and glucomannan (viscosity of 1%aqueous solution thereof at 25° C.: 900-1,100 Pa·s) (40 parts byweight).

Subsequently, Composition N and water were weighed out so as to give asolid component concentration of 1% by weight, and dispersed by means ofAce Homogenizer at 15,000 rpm for 10 minutes at 80° C. The dispersionwas filled into a cylindrical glass vessel having an inner diameter of45 mm up to a height of about 45 mm and left to stand at 5° C. for 24hours to obtain a gel composition. The gel strength at 5° C. was 0.11N.When the gel composition was left to stand at 80° C. for 3 hours for thesake of heat treatment, its gel strength (80° C.) increased to 0.33N.Neither separation of water nor deformation was observed. The gelmaintained roughly the same gel strength (0.31N) even when cooled to 5°C. The gel strengths were all measured in the same manner as in Example11.

Example 15

A gel composition was prepared by weighing out water-dispersible drycomposition I, purified guar gum (viscosity of 1% aqueous solutionthereof at 25° C.: 5-6 Pa·s) and water so that the concentrations ofwater-dispersible dry composition I and the guar gum came to 0.9% byweight and 0.1% by weight, respectively, dispersing the mixture by meansof Ace Homogenizer at 15,000 rpm for 10 minutes at 80° C., and thenallowing it to stand at 5° C. for 24 hours. Gel strength at 5° C. was0.09N. When the gel was heat treated (standing at 80° C. for 3 hours),the gel strength increased to 0.12N at 80° C. Neither separation ofwater nor deformation was observed. Even when cooled to 5° C., this gelcomposition maintained roughly the same gel strength (0.11N).

All the gel strengths were measured in the same manner as in Example 11.

Example 16

A gel composition was prepared by weighing out water-dispersible drycomposition J, glucomannan (viscosity of 1% aqueous solution thereofafter standing at 25° C. for 7 hours: 100 Pa·s or higher) and water sothat the concentrations of water-dispersible dry composition J and theglucomannan came to 0.7% by weight and 0.3% by weight, respectively,dispersing the mixture by means of an Ace Homogenizer at 15,000 rpm for10 minutes at 80° C., and then heat-treating it (leaving it to stand at80° C. for 3 hours). The gel strength at 25° C. was 0.10N.

When the gel composition thus obtained was heated to 60° C., thegel-strength became 0.17N. Neither separation of water nor deformationwas observed.

In another experiment, water-dispersible composition J was thrown intohot water of 80° C. and dispersed by means of an Ace Homogenizer at15,000 rpm for 5 minutes to obtain an aqueous dispersion of 1% byweight. On the other hand, glucomannan was thrown into water at 25° C.and swollen for 7 hours to obtain a swollen solution of 1% by weight.After cooling them to 5° C. separately, they were mixed together anddispersed at a ratio of 7:3 (water-dispersible dry compositionJ:glucomanna=7:3) by means of an Ace Homogenizer at 15,000 rpm for 5minutes, and further heat treated at 80° C. for 5 minutes to obtain agel composition. The gel strength was 0.21N at 25° C.

All the gel strengths were measured in the same manner as in Example 11.

Example 17

Water-dispersible dry composition J was thrown into hot water at 80° C.and dispersed by means of an Excel Autohomogenizer (Model ED-7,manufactured by Nippon Seiki, Co., Ltd.) at 15,000 rpm for 10 minutes,after which tara gum was added and dispersed at 15,000 rpm for 10minutes to obtain a liquid mixture containing 0.9% by weight of thewater-dispersible dry composition J and 0.1% by weight of the tara gum.The resulting mixture was left to stand at 5° C. for 72 hours to obtaina gel composition. Gel strength thereof was 0.15N at 25° C. When it washeated to 60° C., the gel strength increased to 0.17N. Neitherseparation of water nor deformation was observed. All the gel strengthswere measured in the same manner as in Example 11.

Comparative Example 1

Commercially available wood pulp (average degree ofpolymerization=1,050, α-cellulose content=97% by weight) was cut into6×16 mm rectangles and dipped into a sufficient amount of water. Afterascertaining that the pulp had wholly been wet with water, the water waslightly swished off on a sieve. At that time, concentration of solidcomponent was 76% by weight. When the wet pulp was passed once through acutter mill (“Comitrol” Model 1700, cutting head blade distance: 2.03mm, impeller rotation speed: 3,600 rpm), the fiber length came to0.75-3.25 mm.

The cutter mill-treated product and water were weighed out so as to givea fiber content of 2% by weight, and the mixture was agitated until noentanglement between fibers was observed. The aqueous dispersion thusobtained was treated with a whetstone-rotation type pulverizer(“Cerendipiter” Model MKCA6-3, manufactured by Masukou Sangyo, Co.,Ltd.; grinder: MKE6-46, grinder rotation speed: 1,800 rpm). Thetreatment was carried out twice while altering the grinder clearance to110→80 μm, respectively. The aqueous dispersion thus obtained had asedimentation volume of 90% by volume.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to make the concentration 1% by weight, and the diluted dispersionwas passed through a high pressure homogenizer eight times (8 times)(“Microfluidizer” Model M-110Y, treatment pressure: 110 MPa) to obtainaqueous cellulose dispersion a. A 0.25% viscosity thereof was 36 mPa·s.When it was observed by means of an optical microscope and amedium-resolution SEM, a fibrous cellulose having a major axis of40-1,000 μm, a minor axis of 1-65 μm and a major axis/minor axis ratioof 4-100 was observed. When made into a 0.5% by weight aqueous solution,its loss tangent was 1.1. Although it was attempted to measure the waterretention thereof, a part of the sample passed through the cup filterand the remainder caused clogging, so that the value could not bedetermined. The content of the “component stably dispersible in water”was 18% by weight.

Comparative Example 2

Commercially available wood pulp (average degree ofpolymerization=1,210, α-cellulose content=94% by weight) was cut into6×16 mm rectangles and dipped into a sufficient amount of water. Afterascertaining that the pulp had been wholly wet with water, the water wasswished off on a sieve. At that time, concentration of the solidcomponent was 78% by weight. When the wet pulp was passed once through acutter mill (“Comitrol” Model 1700, cutting head blade distance 2.03 mm,impeller rotation speed 3,6000 rpm), the fiber length came to 0.25-3.25mm.

The cutter mill-treated product and water were weighed out so as to givea fiber concentration of 2% by weight, and the mixture was agitateduntil no entanglement between fibers was observed. The aqueousdispersion thus obtained was treated with a whetstone-rotation typepulverizer (“Cerendipiter” Model MKCA6-3, grinder: MKE6-46, grinderrotation speed: 1,800 rpm). The treatment was carried out twice whilealtering the grinder clearance to 110→80 μm, respectively. The aqueousdispersion thus obtained had a sedimentation volume of 88% by volume.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to make the concentration 1% by weight, and the diluted dispersionwas passed through a high pressure homogenizer eight times (8 times)(“Microfluidizer” Model M-110Y, treatment pressure: 110 MPa) to obtainaqueous cellulose dispersion b. A 0.25% viscosity thereof was 56 mPa·s.When it was observed by means of an optical microscope, a fibrouscellulose having a major axis of 50-1,050 μm, a minor axis of 1-50 μmand a major axis/minor axis ratio of 4-150 was observed. The losstangent was 0.92. Although it was attempted to measure water retentionthereof, a part of the sample passed through the cup filter but theremainder caused clogging, so that the value could not be determined.The content of the “component stably dispersible in water” was 25% byweight.

Comparative Example 3

Commercially available cellulose powder (average degree ofpolymerization=390, α-cellulose content=72% by weight) was dispersed inwater so as to give a concentration of 3% by weight. The fiber lengthwas 0.005-2 mm. The aqueous dispersion was treated with a whetstonerotation type pulverizer (“Cerendipiter” Model MKCA6-3, grinder:MKGAW6-80, grinder rotation speed: 1,800 rpm). The treatment was carriedout twice while altering the grinder clearance to 80 and 50 μm,respectively. The aqueous dispersion thus obtained had a sedimentationvolume of 78% by volume.

Subsequently, the aqueous dispersion thus obtained was diluted withwater to make the concentration 1% by weight, and the diluted dispersionwas passed through a high pressure homogenizer eight times (8 times)(“Microfluidizer” Model M-110Y, treatment pressure: 110 MPa) to obtainaqueous cellulose dispersion c. A 0.25% viscosity thereof was 69 mPa·s.When it was observed by means of an optical microscope, a fibrousparticle having a major axis of 5-60 μm, a minor axis of 1-30 μm and amajor axis/minor axis ratio of 3-25 was observed. The loss tangent was1.8. Although it was attempted to measure the water retention thereof,the whole sample passed through the cup filter, so that the value couldnot be determined. The content of the “component stably dispersible inwater” was 69% by weight. However, when it was observed by means of ahigh resolution SEM, the fiber was found to be highly shortened and tohave a major axis of 0.2-1 μm, a minor axis of 20-70 nm and a majoraxis/minor axis ratio of 6-30.

Examples 18-27

By using water-dispersible cellulose A, aqueous suspension-formcompositions B to G and water-dispersible dry compositions H to J as theproducts of the present invention, cocoa drinks were prepared. First,the ingredients and hot water (80° C.) were weighed out so that theconcentrations of the ingredients came to as follows: the product of thepresent invention 0.05% (solid), cocoa powder 0.5%, whole milk powder0.8%, granulated sugar 5.0%, emulsifier (monoglyceride stearate ofmedium purity) 0.2%, and edible salt 0.05%. The mixture was agitated for10 minutes with a propeller agitator at 600 rpm at 80° C., provided thatin the cases of water-dispersible dry compositions H and I, they wereexceptionally used after being subjected to preliminarily dispersion(0.5% aqueous dispersion was dispersed with an Ace Homogenizer at 15,000rpm for 15 minutes, at 80° C.).

Subsequently, the dispersion was twice subjected to a homogenizingtreatment with a piston type homogenizer at 15 and 20 MPa, respectively,poured into a glass-made pressure-resistant bottle, and sterilized at121° C. for 30 minutes. After cooling the sterilized mixture to a roomtemperature with running water, it was shaken about 10 times and stirredby hand, and then allowed to stand in an atmosphere of 60° C. for oneweek.

In cocoa drinks, important problems include (1) that the cocoa particlesprecipitate over time and adhere to the bottom of a container, (2) thatthe once precipitated cocoa particles are difficult to re-disperse evenby shaking the container, (3) that the milk components and the oilycomponent of cocoa separate and gather in the upper part of the drink(oil-off), and (4) that addition of a stabilizer causes a rise inviscosity and deterioration of swallowing feel (mouth feel), etc. Theresults of evaluations as to these items are summarized in Table 1.

TABLE 1 Evaluation of cocoa drinks Examples 18 19 20 21 22 23 24 25 2627 Products of the present invention Water- Aqueous Water- dispersiblesuspension-form dispersible dry cellulose composition composition A B CD E F G H I J Viscosity (mPa · s) *1 5.9 6.1 4.4 2.4 7.2 4.6 3.5 4.6 5.15.5 Volume of cocoa 100 100 32 23 85 45 52 20 29 35 powder layer (%) *2Adhesion of cocoa to None None None None None None None None None Nonecontainer bottom Re-dispersibility of — — 1 1 1 1 1 1 1 1 cocoa powderlayer (times) *3 Oil-off None None None None None None None None NoneNone *1 Viscosity was measured just after preparation of sample (B-typeviscometer with BL adapter, rotor rotation speed 12 rpm, at 25° C.). *2Expressing the % by volume of cocoa powder layer in drink. When it is100%, cocoa powder is uniformly suspended in the drink. When it is 1%,most of the cocoa powder precipitates and adheres to the bottom ofcontainer. *3 An operation of turning the container upside down and thenreturning it to original position is counted as one. The number ofrepetition of the operation needed for re-dispersing the cocoa powderlayer to make the system uniform is usedfor the evaluation, (-: notcoming under the condition). A smaller number means a betterre-dispersibility, which is preferable.

It is apparent from the results that the product of the presentinvention brought about an effect of completely suspending cocoa or aneffect of making re-dispersion of the precipitated cocoa easy, even ifsome extent of precipitation is observed, with a small amount as 0.05%of the product. In addition, there was an effect of preventing theoil-off, while maintaining a relatively low viscosity.

Comparative Examples 4 and 5

Cocoa drinks were prepared and evaluated according to Example 14, exceptthat the products of the present invention were replaced with acommercially available fine cellulose (“Ceolus Cream” FP-03,manufactured by Asahi Kasei Kabushiki Kaisha). For these compositveexamples, the amount of the fine cellulose (solid) was 0.05% by weightand 0.4% by weight, respectively. The results of the evaluation areshown in Table 2.

The fine cellulose used had a 0.25% viscosity of 1 mPa·s. Although ithad a rather obscure particle shape as observed under an opticalmicroscope, its major axis was about 5-10 μm, minor axis was about 1-2μm and major axis/minor axis ratio was about 5. The loss tangent was notmeasurable because its viscoelasticity was lower than the detectionlimit of the apparatus. Although it was attempted to measure its waterretention, the whole sample passed through a cup filter so that thevalue could not be determined. The content of the component obtained bythe method for measuring the content of the “component stablydispersible in water” was 65% by weight. When both samples were observedby means of a high resolution SEM, rod-like particles having a majoraxis of 100-300 nm, a minor axis of 20-50 nm, and a major axis/minoraxis ratio of 4-10 were observed.

Comparative Examples 6 and 7

Cocoa drinks were prepared and evaluated according to Example 14, exceptthat the products of the present invention were replaced withcommercially available microfibrillated cellulose (“Celish” FD-100G,manufactured by Daicel Kagaku Kogyo, Co., Ltd.). The amounts (solid) ofthe microfibrillated cellulose were 0.05% and 0.4% by weight. Results ofthe evaluation are listed in Table 2.

A 0.25% viscosity of the microfibrillated cellulose used was 41 mPa·s.When observed under an optical microscope, the shape of the particleswas as follows: major axis 100-500 μm, minor axis 2-40 μm, and majoraxis/minor axis ratio 10-200. Its loss tangent was 0.64, and its waterretention was 390%. The content of the component obtained by the methodfor measuring the content of the “component stably dispersible in water”was 14% by weight. When the component was observed by means of a highresolution SEM, fibrous particles having a major axis of 1-20 μm, aminor axis of 10-100 nm and a major axis/minor axis ratio of 10-300 wereobserved.

Comparative Examples 8-11

Cocoa drinks were prepared and evaluated according to Example 14, exceptthat the products of the present invention were replaced with aqueouscellulose dispersions a to c, and the product of the present inventionwas absent (blank) in the other example. The amount of the aqueousdispersion of cellulose was adjusted at 0.05% by weight as expressed interms of solid component. The results of the evaluation are shown inTable 2.

TABLE 2 Evaluation of cocoa drinks Comparative Example 4 5 6 7 8 9 10 11Comparative product Aqueous Fine Microfibrillated cellulose dispersioncellulose cellulose a b c Blank Amount of 0.05 0.4 0.05 0.4 0.05 0.050.05 0 comparative product (solid) (%) Viscosity (mPa · s) *1 1.7 2.71.9 3.4 1.8 1.6 1.6 1.6 Volume of 1 63 1 56 1 1 1 1 cocoa powder layer(%) *2 Adhesion of cocoa Found None Found Found Found Found Found Foundto container bottom Re-disdpersibility 12 1 11 5 12 13 9 15 of adheredcocoa/cocoa powder layer (times) *3 Oil-off Found None None None NoneNone None Found *1 Viscosity was measured just after preparation of thesample (B-type viscometer with BL adapter, rotor rotation speed 12 rpm,at 25° C.). *2 Expressing % by volume of cocoa powder layer in drink.When it is 100%, the cocoa powder is uniformly suspended in the drink.When it is 1%, most of the cocoa powder precipitates and adheres to thebottom of container. *3 An operation of turning the container upsidedown and returning it to its original position is counted as one. Thenumber of repetition needed to re-disperse the adhered cocoa powder andthe cocoa powder layer, to make thesystem uniform, was evaluated. Asmaller number means a better re-dispersibility, which is preferable.

Although the fine cellulose and microfibrillated cellulose could exhibiteffects similarly to those of the products of the present invention,these materials had to be used in an amount about 8 times as large asthe product of the present invention.

Examples 28-30

Sour milk drinks were prepared with aqueous suspension-form compositionsC and F and water-dispersible dry composition I of the presentinvention. First, pectin (“UNIPECTIN” AYD-358, manufactured by SYSTEMSBIO-INDUSTRIES) was dissolved in hot water at 80° C. to prepare a 2% byweight aqueous solution. The solution was stored overnight at 5° C.Then, the product of the present invention, a commercially availablefive-fold concentrated acid milk, 2% aqueous pectin solution and waterwere weighed out so as to give the concentration of the product of thepresent invention of 0.003% (solid content), the concentration of thefive-fold concentrated acid milk of 20% and the concentration of the 2%aqueous pectin solution of 1.5%. The mixture was then agitated for 5minutes (propeller agitation, 500 rpm, room temperature); provided thatin the case of the water-dispersible dry composition I, it was usedafter being subjected to preliminary dispersion, namely dispersion of0.5% aqueous dispersion thereof with an Ace Homogenizer at 15,000 rpmfor 15 minutes at 80° C.

Next, it was subjected to a homogenizing treatment with a piston typehomogenizer (15 MPa), heated and sterilized at 85° C. for 10 minuteswhile agitating it with a propeller, poured into a glass container,cooled to a room temperature with running water, shaken and agitated byhand about 10 times, and thereafter left to stand in an atmosphere of60° C. for 3 days.

Problems of sour milk drinks include: (1) that the milk proteinparticles precipitate over time and adhere to the container bottom, (2)that the once precipitated milk protein particles cannot readily bere-dispersed even if the container is shaken, (3) that if a stabilizeris added excessively, viscosity rises even though suspension stabilityincreases, and the mouth feel is thereby adversely affected (a pastyfeeling appears). The results of evaluations as to these items arelisted in Table 3.

TABLE 3 Evaluation of sour milk drinks Examples 28 29 30 Products of thepresent invention Water- Aqueous dispersible suspension-form drycomposition composition C F I Viscosity (mPa · s) *1 3.1 3.2 3.0 Volumeof sedimented 2 2 2 milk protein (%) Re-dispersibility of 2 2 4sedimented milk protein (times) *2 *1 Viscosity was measured just afterpreparation of the sample (B-type viscometer with BL adapter, rotorrotation speed 12 rpm, at 25° C.). *2 An operation of turning thecontainer upside-down and then returning it to the original position iscounted as one. Re-dispersibility of sedimented milk protein isevaluated by counting the numberof operations needed for re-dispersingand making the sedimented milk protein disappear. A smaller number meansa better re-dispersibility, which is preferable.

It is apparent from the results, although the products of the presentinvention could not prevent the sedimentation of milk protein particles,the improved the re-dispersibility of sedimented milk protein particles,even when used in very small amounts. Though the viscosity was at most3.2 mPa·s, the viscosity was hardly felt upon drinking, and no pastyfeel was perceived.

Comparative Examples 12-18

Sour milk drinks were prepared and evaluated for the cases where thesame fine cellulose as used in Comparative Example 4, the samemicrofibrillated cellulose as used in Comparative Example 5 and aqueousdispersion b-c at a prescribed concentration were used instead of theproduct of the present invention and the case where the product of thepresent invention was absent (blank). The results of the evaluation areshown in Table 4.

TABLE 4 Evaluation of cocoa drinks Comparative Example 12 13 14 15 16 1718 Comparative produce Aqueous cellulose Microfibrillated dispersionFine cellulose cellulose b c Blank Amount of 0.003 0.05 0.003 0.05 0.0030.003 0 comparative product (solid) (%) Viscosity 2.2 2.4 2.2 2.5 2.22.3 2.2 (mPa · s) *1 Volume of 1 2 1 3 1 1 1 sedimented milk proteinpowder layer (%) *2 Re- 44 3 10 4 11 30 46 dispersibility of sedimentedmilk protein (times) *1 Viscosity was measured just after preparation ofsample (B-type viscometer with BL adapter, rotor rotation speed 12 rpm,at 25° C.). *2 An operation of turning the container upside-down andthen returning it to the original position is counted as one.Re-dispersbility of sedimented milk protein is evaluated by counting thenumber of operations needed for re-dispersing andmaking the sedimentedmilk protein disappear. A smaller number means a betterre-dispersibility, which is preferable.

Although fine cellulose and microfibrillated cellulose could also exertsimilar effects to those of the product of the present invention, theyhad to be used in an amount 10 times as large as that of the presentinvention or more.

Examples 31-33

Water-dispersible dry composition H, I or J was added to hot water anddispersed with an Ace Homogenizer (Model AM-T, manufactured by NipponSeiki, Co., Ltd.) at 15,000 rpm for 15 minutes at 80° C. to prepare a0.5% dispersion. To 1-20 parts of this dispersion were added hot water(80° C.), 48 parts of coffee extract solution, 12.5 parts of milk(defatted solid component 8.8%, milk fat 3.8%), 6 parts of sugar, 0.06parts of sodium hydrogen carbonate, and 0.03 parts of sucrose palmiticester. The amount of the hot water was adjusted to give a total amountof 100 parts. The liquid mixture thus obtained was agitated by means ofa propeller at 80° C. for 10 minutes, then twice homogenized with apiston type homogenizer (primary pressure: 15 MPa, secondary pressure: 5MPa) and poured into a glass-made heat-resistant bottle having acapacity of 200 mL. It was sterilized at 121° C. for 30 minutes, andcooled with running water to obtain a milk coffee. The milk coffee wasleft to stand in an atmosphere of 5, 25 or 60° C. for one month, and theuniformity of appearance (the presence of oil-off, coagulation,sedimentation) was visually examined. The results are shown in Table 5.Viscosity of samples was measured from the manufacture after one daystorage at 5° C.), using a B-type viscometer with a BL adapter, at arotor rotation speed of 60 rpm.

TABLE 5 Results of storage test of milk coffee (one month storage)Amount of water- dispersible Example 31 Example 32 Example 33 dryFormulation I Formulation J Formulation H composition Storagetemperature (° C.) 5 25 60 5 25 60 5 25 60 0.005% Appearance/Oil-off− + + − − + − + + Appearance/Coagulation − − − − − − − − −Appearance/Sedimentation + + + − + + + + + Viscosity (mPa · s) 1.9 1.91.9  0.02% Appearance/Oil-off − − + − − − − − − Appearance/Coagulation −− + − − − − − + Appearance/Sedimentation − + + − − − − − − Viscosity(mPa · s) 2.1 2.2 2.0  0.05% Appearance/Oil-off − − + − − − − − −Appearance/Coagulation − + + − − + − − + Appearance/Sedimentation − − +− − + − − + Viscosity (mPa · s) 3.5 4.0 3.3  0.1% Appearance/Oil-off − −− − − − − − − Appearance/Coagulation − + + + + + − + +Appearance/Sedimentation − + + + + + − + + Viscosity (mPa · s) 7.2 8.36.8 [Criterion for evaluation of appearances] −: Not occurring at all ±:Very slightly occurring +: Occurring ++: Remarkably occurring

Comparative Example 19 mentioned hereinbelow resents a recipe containingno water-dispersible dry composition of the present invention. In thiscase, sedimentation of milk protein and oil-off were observed.Contrariwise, according to the present examples, the sedimentation andoil-off were remarkably suppressed due to addition of water-dispersibledry composition; provided that an increase in the amount of compositematerial tends to promote coagulation to some extent. The expression “±”namely “very slightly occurring” means a state where the system caneasily be made uniform by shaking it with hand, and which is good enoughto be used practically.

Example 34

A milk coffee was prepared in the same manner as in Example 31, exceptthat water-dispersible dry composition I was replaced with aqueoussuspension-form composition F. The amount of F in the milk coffee was0.025% as a solid. The results of the evaluation carried out in the samemanner as in Example 31, are shown in Table 6.

Example 35

A milk coffee was prepared in the same manner as in Example 31, exceptthat the water-dispersible dry composition I was replaced with aqueoussuspension-form composition C and ι-carrageenan was compounded. Theamount of C was 0.02% as expressed in terms of solid component.ι-carrageenan was added in an amount of 0.005%. The results of theevaluation as in Example 31 are shown in Table 6.

TABLE 6 Results of storage test of milk coffee (one month storage)Example 34 Example 35 Storage temperature (° C.) 5 25 60 5 25 60Appearance/Oil-off − ± ± − ± ± Appearance/Coagulation − − ± − − ±Appearance/Sedimentation − − ± − − ± Viscosity (mPa · s) 2.3 2.2(Criterion for evaluation of appearances) −: Not occurring at all ±:Very slightly occurring +: Occurring ++: Remarkably occurring

Comparative Example 19

A milk coffee was prepared in the same manner as in Example 31, exceptthat the water-dispersible dry composition I was not used. Results ofevaluation as in Example 31 are shown in Table 7.

In this recipe, a stabilizer was not particularly added, except that abacteriostatic emulsifier (sucrose palmitic ester) was added. In thiscase, sedimentation of milk protein and oil-off were observed. It isdifficult to commercialize the milk coffee in such a state, even if itis packaged in a can.

Comparative Example 20

A milk coffee was prepared in the same manner as in Example 31, exceptthat 0.2 part of high-purity monoglyceride stearate was added and thewater-dispersible dry composition I was not used. Results of the sameevaluation as in Example 31 are shown in Table 7.

When stored at 25° C., a severe coagulation of the milk component wasobserved. At 60° C., a little oil-off and a clear sedimentation wereobserved.

Comparative Example 21

A milk coffee was prepared in the same manner as in Example 31, exceptthat 0.2 part of high-purity monoglyceride stearate and 0.1 part of acrystalline cellulose preparation (“Avicel” RC-591, manufactured byAsahi Kasei Kabushiki Kaisha) were added, and the water-dispersible drycomposition I was not used. Results of evaluation as in Example 31 areshown in Table 7. This Comparative Example represents the techniquedisclosed in JP-A-6-335348.

Comparative Example 22

A milk coffee was prepared in the same manner as in Example 31, exceptthat 0.2 part of high-purity monoglyceride stearate and 0.3 part of amicrocrystalline cellulose preparation (“Avicel” RC-591, manufactured byAsahi Kasei Kabushiki Kaisha) were added, and the water-dispersible drycomposition I was not used. Results of the evaluation as in Example 31are shown in Table 7. This Comparative Example represents the techniquedisclosed in JP-A-6-335348.

TABLE 7 Results of storage test of milk coffee (one month storage)Comparative Comparative Comparative Comparative Example 19 Example 20Example 21 Example 22 Storage temperature (° C.) 5 25 60 5 25 60 5 25 605 25 60 Appearance/Oil-off ± + + − *1 ± − − − − − −Appearance/Coagulation − − − ++ ++ − + − − − − ±Appearance/Sedimentation + + ++ ± *2 + ± + + ± − ± Viscosity (mPa · s)1.9 2.2 2.8 4.7 [Criterion for evaluation of Appearance] −: Notoccurring at all, ±: Very slightly occurring, +: Occurring, ++:Remarkably occurring *1 Although no oil-off was observed, it was due tothe strong coagulation of milk component. *2 Although no sedimentationwas observed, it was due to strong coagulatoin of milk component.

It is apparent that, in Comparative Example 21, the stability in storageat 60° C. increased due to the addition of 0.2 part of emulsifier and0.1 part of microcrystalline cellulose preparation. However, none of thestabilities at 5, 25 and 60° C. can be considered sufficient. InComparative Example 22, the state of the milk coffee became very good at5 and 25° C. due to the addition of 0.2 part of emulsifier and 0.3 partof microcrystalline cellulose preparation. At 60° C., however, a severecoagulation occurred.

Examples 36-39

A sesame sauce for SHABUSHABU (sliced beef boiled with vegetables) withthe following formulation was prepared by the use of the aqueoussuspension-form compositions C and F and water-dispersible drycompositions H and J. First, the ingredients other than vinegar wereagitated by means of a rotational homogenizer at 55° C. for 5 minutes,and then vinegar which had been twice diluted with water was added, andthe resulting mixture was further agitated at 55° C. for 5 minutes. Atthis time, the water-dispersible dry compositions H and J were usedafter preliminary dispersion of 1.5% aqueous dispersion thereof with arotational homogenizer at 10,000 rpm for 60 minutes at 80° C. Theformation of the sesame sauce was shown in the following: granulatedsugar 30%, sesame oil 7%, sesame paste 5%, edible salt 4%, vinegar 2%,product of the present invention 0.2% (solid) and xanthan gum 0.05%, theremainder being water. Then, the mixture was poured into a glasscontainer, tightly stoppered, and heated and sterilized at 80° C. for 20minutes. The sesame sauce sample thus obtained was left to stand at 25°C. for one month.

The sesame sauce is required to have an appropriate body feel(viscosity), as well as the stability of the system enough to preventthe separation of the sesame paste and oily component. The results ofthe evaluation of these properties are shown in Table 8.

TABLE 8 Results of evaluation of sesame sauce for SHABUSHABU Example 3637 38 39 Product of the present invention Aqueous suspension-formWater-dispersible composition dry composition C F H J Viscosity 320 342331 360 (mPa · s) *1 Stability *2 Uniform Uniform Uniform Uniform statewith no state with no state with no state with no separation separationseparation separation nor nor nor nor coagulation coagulationcoagulation coagulation *1 Viscosity was measured just after preparationof sample (rotational viscometer, shearing velocity 20 s⁻¹, at 25° C.).The viscometer used was Model RM-180, manufactured by RheometricScientific Inc. *2 Stability was evaluated by visually examining theappearance.

Comparative Examples 23-29

Sesame sauces for SHABUSHABU were prepared according to Example 36, forthe cases where the microfibrillated cellulose of Comparative Example 6and aqueous cellulose dispersion c were used at prescribedconcentrations, the case where the product of the present invention wasnot used (blank), and the case where the amount of xanthan gum wasincreased to 0.3% without blending the product of the present invention.The results of the evaluation are shown in Table 9.

TABLE 9 Results of evaluation of sesame sauce for SHABUSHABU ComparativeExample 23 24 25 26 27 28 29 Comparative product Aqueous Xanthandispersion gum- Fine Microfibrillated of increased cellulose cellulosecellulose Blank system Amount of 0.2 1 0.2 1 0.2 0 0 comparative product(solid) (%) Viscosity 212 225 220 290 240 207 — (mPa·s) *1 Stability *2Transparent Transparent Transparent Transparent Transparent Transparentgelation layer (29%) layer (8%) layer (22%) layer (6%) layer (11%) layer(32%) formed in formed in formed in formed in formed in formed in thelower the lower the lower the lower the lower the lower part part partpart part part *1 Viscosity was measured just after preparation ofsample (rotational viscometer, shearing velocity 20 s⁻¹, at 25° C.). Theviscometer used was Model RM-180, manufactured by Rheometric ScientificInc. *2 Stability was evaluated by visually examining the appearance.

The blank sample is low in viscosity and separation was observed(Comparative Example 28). The xanthan gum-increased system formed a gel,probably due to some interaction between the protein component in sesameand xanthan gum. On the other hand, none of the other comparativeexamples showed a sufficiently high stability, even though some of themshowed a relatively high viscosity.

Comparative Examples 40-42

Using aqueous suspension-form compositions C and F and water-dispersibledry composition H as the products of the present invention, low-fatmayonnaise type dressings were prepared with the formulations mentionedbelow. First, water, a product of the present invention, xanthan gum andegg yolk were agitated in a Hobart mixer for 5 minutes at 150 rpm. Then,while continuing the agitation, rape seed oil was added at a rate of 20g/min. and further agitated for 10 minutes. Subsequently, seasoningmixture powder and vinegar were added and further agitated for 5minutes. Finally, the mixture was homogenized with a colloid mill(clearance: 10 mil, rotor rotation speed: 3,000 rpm) to obtain adressing. The formulation of mixture was as follows: rape seed oil 35%,egg yolk 10%, vinegar 7%, product of the present invention 0.4% (solid),mixed seasoning powder (edible salt/salt/mustard powder/Naglutamate=26/9/4/1) 4%, and xanthan gum 0.3%, the remainder being water.Only the water-dispersible dry composition H was subjected to apreliminary dispersing treatment, namely dispersing a 1.5% aqueousdispersion thereof with a rotational homogenizer at 10,000 rpm for 60minutes at 80° C., before being used.

The low-fat mayonnaise type dressing is required to have an appropriatebody feel, and a sharp mouth feed without a pasty feel. The results ofthe evaluation of these properties are shown in Table 10.

Comparative Examples 30-32

A low-fat mayonnaise type dressings were prepared and evaluatedaccording to Example 40 for the cases where the fine cellulose ofComparative Example 4 and the microfibrillated cellulose of ComparativeExample 6 were used at prescribed concentrations, and the case where theamount of xanthan gum was increased to 0.6% without blending the productof the present invention. Results of their evaluation are shown in Table10.

TABLE 10 Results of evaluation of low-fat mayonnaise type dressingsExample/Comparative Example Example Comparative Example 40 41 42 30 3132 Product of the present invention/Comparative product Aqueous Water-suspension-form dispersible 0.6% xanthan composition dry compositionFine Micro fibrous gum-containing C F H cellulose cellulose systemAmount of product of  0.4  0.4  0.4  2.5 1.5 0  the presentinvention/Comparative product (solid) (%) Viscosity (Pa.s)*1 22.0 21.320.8 21.1 20.5 19.1 Mouth feel Sharp feel Sharp feel Sharp feel Sharpfeel Sharp feel Pasty mouth without without without pasty withoutwithout pasty feel pasty feel pasty feel feel pasty feel feel *1Viscosity was measured with rotational viscometer (Model RM180,manufactured by Rheometric Scientific Inc., Shear Rate 50 s⁻¹, at 25°C.).

When the product of the present invention was used, the dressings had abody (viscosity) comparable to that of regular (not low-fat) mayonnaise,and exhibited sharp but non-pasty mouth feel. On the other hand, in thecases where the fine cellulose and the microfibrillated cellulose wereused, the amount of 2.5% or 1.5% thereof was necessary for obtaining asimilar body. In the case of compounding xanthan gum only, a comparableviscosity was obtained by using it in an amount of 0.6%, but thedressing had a pasty mouth feel characteristic of water-soluble gum.

Examples 43-45

A custard pudding-like gel was prepared by using the water-dispersibledry compositions H, I and J as products of the present invention. First,the composition was weighed out so that the concentration of the productof the present invention came to 1%, hot water was added thereto, andthe mixture was homogenized with an Ace Homogenizer at 15,000 rpm for 10minutes at 80° C. To 5 parts of the dispersion were added hot watertogether with 10 parts of sugar, 8 parts of skim milk powder, 3 parts ofcoconut oil, 1 part of egg yolk, 0.5 parts of gelatin, 0.2 parts ofagar, and 0.2 parts of glycerin fatty acid ester. After agitating andmixing the resulting mixture at 85° C. for 15 minutes, the mixture wasone-pass treated with piston type homogenizer at 15 MPa to obtain acustard pudding solution. All the powdery starting materials as abovewere charged as calculated in terms of dry weight. Then, hot water wasadded so as to give a total weight of 100 parts.

Next, the custard pudding solution was filled into a glassheat-resistant bottle having a capacity of 100 mL, cooled in anatmosphere of 5° C. for one hour, and then heated and sterilized at 105°C. for 30 minutes to obtain a custard pudding-like gel. After allowingthe gel to stand in an atmosphere of 5° C. for 24 hours, the appearanceand mouth feel were evaluated. As a result, all the sample showed auniform appearance without coagulation of milk protein or a transparentgel part formed by separation of milk component. As compared with thesamples of Comparative Example 33 mentioned below, its mouth feel wassmooth, fine in texture, and free of roughness.

Comparative Example 33

A custard pudding-like gel was prepared in the same manner as in Example43, except that the water-dispersible dry composition H was not used.After allowing it to stand in an atmosphere of 5° C. for 24 hours, itwas evaluated on appearance and mouth feel. As a result, the milkprotein coagulated finely, and small amounts of transparent gels wereformed at the bottom of container or in the upper part. The mouth feelwas coarse-grained with a little roughness.

Example 46

A powdered green tea-pudding was prepared by using the water-dispersibledry composition J of the present invention. First, water-dispersible drycomposition J was weighed out so that its concentration came to 1%, andadded to hot water, and dispersed by means of an Ace Homogenizer at15,000 rpm for 10 minutes at 80° C. To 5 parts of this dispersion wasadded hot water together with 12 parts of sugar, 7 parts of skim milkpowder, 3 parts of coconut oil, 1.2 parts of powdered green tea, 1 partof egg yolk, 0.25 parts of κ-carrageenan, 0.2 parts of Locust bean gum,0.2 parts of xanthan gum, and 0.2 parts of glycerin fatty acid ester.After agitating and mixing the mixture at 85° C. for 15 minutes, it wasone-pass treated with a piston type homogenizer at 15 MPa to obtain apowdered green tea pudding solution. All the powdery starting materialswere charged as calculated in terms of dry material, and hot water wasadded so as to give a total weight of 100 parts.

Subsequently, the pudding solution was filled in a 100 mL glass,heat-resistant bottle, and cooled in an atmosphere of room temperaturefor one hour to obtain a powdered green tea pudding. The pudding washeated and sterilized additionally at 105° C. for 30 minutes. Both thesamples obtained above were left to stand in an atmosphere of 5° C. for24 hours, after which their appearance and mouth feel were evaluated. Asa result, both samples showed a uniform appearance wherein the green teapowder was present throughout the pudding. The mouth feel thereof was offine-texture without rough feel, and the taste thereof remained constantuntil they were all eaten.

Comparative Example 34

A powdered green tea pudding was prepared in the same manner as inExample 46, except that the water-dispersible dry composition J was notused. In the sample before sterilization, a part of the powdered greentea precipitated to the bottom of the container. Although the mouth feelwas good with a fine-texture, the taste varied from one part to another.In the sample after the sterilization, the powdered green tea had almosttotally precipitated.

Example 47

A fruit juice-containing jelly was prepared by the use of thewater-dispersible dry composition I of the present invention. First,water-dispersible dry composition I was weighed out so thatconcentration thereof came to 1%, added to hot water, and dispersed withan Ace Homogenizer at 15,000 rpm for 10 minutes at 80° C. Water and 7.5parts of grapefruit juice (concentrated to 5 times its originalconcentration) were added to 10 parts of the dispersion and heated to85° C., after which 10 parts of sugar, 4 parts of indigestible dextrin,0.2 part of de-acylated Gellan gum and 0.1 part of calcium lactate wereadded and agitated to prepared a jelly solution. All the powderymaterials were charged as calculated in terms of dry materials. Thewater was added so as to give a total amount of 100 parts.

Subsequently, the jelly solution was filled into a 100 mL glass,heat-resistant bottle and cooled in an atmosphere of 5° C. for one hour,after which it was heat-sterilized at 80° C. for 30 minutes or at 105°C. for 30 minutes to obtain a grapefruit juice-containing jelly. Afterallowing it to stand in an atmosphere of 5° C. for 24 hours, theappearance and mouth feel were evaluated. As a result, the productsterilized at 80° C. for 30 minutes was free of separation of water andcrack formation, and showed a uniform appearance. The gel strength was0.53N. The product sterilized at 105° C. for 30 minutes was also uniformin appearance and gel strength thereof was 0.51N. The mouth feelsthereof were somewhat more intense in the juice taste as compared withthe product of Comparative Example 35 (mentioned below) where thewater-dispersible dry composition I was not added. The break-downpattern thereof was somewhat elongating. The mode of breaking thereofwas fine in texture and smooth.

The gel strength (breaking strength) was measured without removing thejelly from the container, but directly in the bottle from which the lidhad been removed, by means of “RHEO METER” Model NRM-2002J, manufacturedby Fudo Kogyo, Co., Ltd., with a pushing-in in jig (10 mmφsphericaljig), at a pushing speed of 6 cm/min.

Comparative Example 35

A grapefruit juice-containing jelly was prepared in the same manner asin Example 47, except that the water-dispersible dry composition I wasnot used. After allowing it to stand in an atmosphere of 5° C. for 24hours, it was evaluated on appearance and mouth feel. As a result, aproduct sterilized at 80° C. for 30 minutes was free of separation ofwater and cracks and showed a uniform appearance. The gel strength was0.60N. However, a product sterilized at 105° C. for 30 minutes, allowedseparation of water on its upper surface, with formation of some cracks.Further, the concentration of fruit juice component was uneven, and theappearance was not uniform. The gel strength was 0.65N. (The high gelstrength is probably due to shrinkage of gel, as suggested from theseparation of water). In both cases, the mouth feels were hard andbrittle (crispy), which was characteristic of Gellan gum. When it wastentatively crushed with tongue or teeth, it was difficult to crushfinely and completely.

Example 49

A carrot jelly was prepared by the use of the gel-forming composition Nof the present invention. To 72 parts of hot water (80° C.) were added18 parts of steamed carrot, 4.5 parts of sugar, 4.5 parts of lemon juiceand 1 part of the gel-forming composition N, and the mixture wasdispersed. The dispersion was poured into a glass, heat-resistant bottlehaving an inner diameter of 45 mm and heat-sterilized at 80° C. for 30minutes. Thus, a carrot jelly, free from water separation, coagulationand sedimentation of carrot fiber, was obtained. The gel strength was0.09N. When it was heated at 60° C., it showed neither dissolution norseparation of water. The gel strength was 0.11N at 60° C.

The gel strength (breaking strength) was measured without removing thejelly from the container, but was measured directly in the bottle fromwhich the lid had been removed, by means of “RHEO METER” ModelNRM-2002J, manufactured by Fudo Kogyo, Co., Ltd., with a pushing-in jig(10 mmφspherical jig), at a pushing speed of 6 cm/min.

Comparative Example 36

Eighteen parts of steamed carrot, 4.5 parts of sugar, 4.5 parts of lemonjuice, and 1.4 parts of gelatin were dispersed in 71.6 parts of hotwater having a temperature of 80° C. and poured into a glass,heat-resistant bottle having an inner diameter of 45 mm. When it wasimmediately cooled to 5° C., separation of water was not observed, butmost of the carrot precipitated to leave a transparent jelly behind asan upper layer. The gel strength was 0.07N at 5° C. When it was heatedto 60° C., the gel melted, and the carrot precipitated completely.

Example 50

A rice-containing gel was prepared, using the gel-forming composition Nof the present invention, to provide food for nursed patients. First, to28.6 parts of commercially available retort rice 70.4 parts of water wasadded and agitated by means of a domestic mixer for 5 minutes. Then, 1part of the product of the present invention was added, and theresulting mixture was dispersed with a rotational homogenizer (“T. K.Homomixer MARK II” Model 2.5 manufactured by Tokushu Kikakogyo, Co.,Ltd.) at 6,000 rpm for 15 minutes, and packed into a glass-madeheat-resistant bottle. After a heat-treatment at 105° C. for 30 minutes,the bottle was cooled with running water and then allowed to standovernight in an atmosphere of 5° C. The gel thus obtained was free fromseparation and coagulation and its gel strength was 0.21N.

The gel strength was measured without taking out the gel compositionfrom the vessel, but directly in the bottle from which the lid had beenremoved, by means of “RHEO METER” Model NRM-2002J, manufactured by FudoKogyo, Co., Ltd., with a pushing-in jig (10 mmφspherical jig), at apushing speed of 2 cm/min.

Example 51

A pumpkin pudding was prepared by the use of the water-dispersible drycomposition J of the present invention, to provide a food for nursedpatients. First, a product of the present invention was added to hotwater and agitated by means of an Ace Homogenizer at 15,000 rpm for 10minutes at 80° C. Then, glucomannan was added thereto and dispersed toobtain a liquid dispersion having a formulation of 1.05% of compositionJ and 0.45% of glucomannan. To 50 parts of this dispersion were added 20parts of steamed pumpkin, 24 parts of milk, 5.4 parts of sugar, 0.1 partof salt-free butter, and 0.1 part of salt, and the mixture was agitatedand mixed together. The mixture was poured into a glass, heat-resistantbottle having an inner diameter of 45 mm and left to stand in anatmosphere of 5° C. for about one hour, and thereafter sterilized at105° C. for 30 minutes. Thus, a uniform pumpkin pudding, which did notseparate or coagulate was obtained. The gel-strength was 0.15N at 25° C.When it was heated to 50° C., it showed a gel strength of 0.12N at 50°C., without melting and without separation of water. When the pumpkinpudding was eaten, the gel was lightly broken in the mouth, showing nopasty feel, and imparting a distinct impression of pumpkin and milk. Itthus believed that the pumpkin pudding can be used for patients who mustavoid solid foods. The pumpkin pudding can be eaten in a warmed state.

The gel strength was measured without taking out the gel compositionfrom the vessel, but directly in the bottle from which the lid had beenremoved, by means of “RHEO METER” Model NRM-2002J, manufactured by FudoKogyo, Co., Ltd., with a pushing-in jig (10 mmφspherical jig), at apushing speed of 2 cm/min.

Comparative Example 37

Hot water having a temperature of 80° C. was added to agar to obtain anaqueous solution of agar having a concentration of 0.4%. To 50 parts ofthe aqueous solution were added 20 parts of steamed pumpkin, 24 parts ofmilk, 5.4 parts of sugar, 0.5 parts of salt-free butter and 0.1 part ofsalt. After agitating and mixing the mixture together, it was pouredinto a glass-made heat-resistant bottle having an inner diameter of 45mm. After allowing it to stand in an atmosphere of 5° C. for about onehour, it was sterilized at 105° C. for 30 minutes. As a result, thesystem coagulated, and the pumpkin fibers gathered on the upper surfaceof the gel. When it was heated to 50° C. and tentatively eaten, ithardly gave the mouth the feel of a gel. The taste of pumpkin and milkwere very thin.

Example 52

A miso soup gel was prepared by the use of the water-dispersible drycomposition H, to provide a food for nursed patients. First, a productof the present invention was added to water at 80° C. and dispersed bymeans of an Ace Homogenizer at 15,000 rpm for 10 minutes at 80° C.Further, glucomannan was added and dispersed to obtain a liquiddispersion having a formulation of 1% of the composition H and 0.43% ofglucomannan. To 70 parts of this dispersion was added a stirred mixtureconsisting of 21 parts of hot water (80° C.), 8 parts of white miso and1 part of bonito-flavor seasoning, and the resulting mixture wasagitated and mixed. The mixture thus obtained was poured into in aglass, heat-resistant bottle having an inner diameter of 45 mm, to whichwere added 5 pieces of TOFU having a shape of about 1 cm square. Thebottle was allowed to stand in an atmosphere of 5° C. for about onehour. Thereafter, it was sterilized at 105° C. for 30 minutes. As aresult, there was obtained a miso soup gel in which the tofu (soy-beamcurd) pieces were uniformly distributed in the whole soup withoutseparation of water and sedimentation. The gel strength was 0.09N at 25°C. When the gel was heated to 50° C., the gel did not melt nor allowseparation of water, keeping a gel strength of 0.07N at 50° C. When itwas eaten, the gel was broken in mouth lightly, showing no pasty feeland clearly exhibiting the tastes of miso and bonito-flavour, withoutany unpleasant feeling as a miso soup.

The gel strength was measured without removing the gel composition fromthe vessel, but was measured directly in the bottle from which the lidhad been removed, by means of a “RHEO METER” Model NRM-2002J,manufactured by Fudo Kogyo, Co., Ltd., with a pushing-in jig (10mmφspherical jig), at a pushing speed of 2 cm/min.

Comparative Example 38

To 90.7 parts of hot water having a temperature of 80° C. were added 8parts of white miso and 1 part of bonito-flavor seasoning, and themixture was agitated and mixed. Further, 0.3 part of native type Gellangum was added thereto, and agitated and mixed. The mixture was filled ina glass-made heat-resistant bottle having an inner diameter of 45 mm, towhich were added 5 pieces of tofu having a shape of about 1 cm square,and the resulting mixture was allowed to stand in an atmosphere of 5° C.for about one hour, after which it was sterilized at 105° C. for 30minutes. As a result, water was separated and two layers were formed(the solid component of miso and the tofu precipitated to the lower 50%volume region). When this product was heated to 50° C., the breakingstrength (50° C.) was 0.06N which was comparable to that of Example 52.However, it had a wiggling texture when eaten, characteristic of nativeGellan gum, which was very different from miso soup.

Example 53

The water-dispersible dry composition I (2.1 g) was weighed out, addedto 297 g of hot water and dispersed by means of an Ace Homogenizer at15,000 rpm for 10 minutes at 80° C. Glucomannan (0.9 g) (Propol A,manufactured by Shimizu Kagaku, Co., Ltd.) was added to the dispersion,and the mixture was further agitated for 10 minutes, and then the waterlost by evaporation was supplemented. Thus, 300 g of a liquid mixturehaving a solid concentration of 1% was obtained. All the powderymaterials were charged as calculated in terms of dry product. The liquidmixture (44 g) was poured into a wide mouth polycarbonate bottle havinga capacity of 125 mL, and heated in a water bath kept at 80° C. for 3hours, then cooled with running water for one hour, and frozen in thefreezing chamber of a domestic freezer-refrigerator at −20° C. for 24hours. Then, it was allowed to stand in an atmosphere of 40° C. for thesake of de-freezing to obtain a gel composition.

A thin piece of this gel was placed on a glass slide and observed underan optical microscope. It was found to have a sponge-like structure. Thepores therein had a size of 20 μm×50 to 300 μm×400 μm. When pushed witha spatula, the gel released water with shrinkage of volume. When asufficient quantity of water was added thereto, the gel absorbed thewater and swelled to recover the original shape. That is, it was asponge-like gel. When this gel had absorbed a sufficient quantity ofwater, it retained 125 times as great an amount of water as its solidweight. When the water was released by applying pressure with a spatula,it retained 20 times the amount of water as its solid weight. When thegel was eaten, a crunchy mouth feel was sensed. The gel strength(breaking strength) was 0.82N.

The gel strength (breaking strength) was measured after cutting the gelcomposition into a cube having a size of 10 mm (height)×20 mm (width)×30mm (length), on which the gel strength was measured by means of a “RHEOMETER” Model NRM-2002J, manufactured by Fudo Kogyo, Co., Ltd., with apushing-in jig (0.3 mm piano wire jig), at a pushing speed of 6 cm/min.

Example 54

A gel composition was obtained in the same manner as in Example 53,except that the water-dispersible dry composition I was replaced withwater-dispersible dry composition J; provided that the freezing wascarried out by dipping the sample in ethanol adjusted to −45° C. withdry ice and thereafter allowing the sample to stand in a freezer kept at−25° C. for 3 hours. The de-freezing was carried out by allowing thesample to stand at room temperature.

A thin piece of this gel was placed on a glass slide and observed underan optical microscope. As a result, it was found to have a sponge-likestructure, the pores of which had a size of 10 μm×20 μm to 50 μm×80 μm.When pushed with a spatula, the gel released water with shrinkage ofvolume. When a sufficient quantity of water was added thereto, the gelabsorbed the water and swelled to recover the original shape. That is,it was a sponge-like gel. When the gel had absorbed a sufficient amountof water, it retained 85 times as great an amount of water as the solidweight thereof. When it was made to release the water by pushing it withthe spatula, it retained 15 times as great an amount of water as itssolid weight. When this gel was eaten, it exhibited a crunchy mouthfeel. The gel strength was 0.56N.

Comparative Example 39

The procedure of Example 53 was repeated, except that thewater-dispersible dry composition I was replaced with a crystallinecellulose complex (“Avicel” RC-591, manufactured by Asahi KaseiKabushiki Kaisha). However, the content after de-freezing had afluidity, and assumed no appearance of gel.

Comparative Example 40

Hot water (294 g) was added to 6 g of commercially availablemicrofibrillated cellulose (“Celish” FD-100G, manufactured by DaicelKagaku Kogyo, Co., Ltd.) and dispersed with an Ace Homogenier at 15,000rpm for 10 minutes, at 80° C. to obtain 300 g of a dispersion having asolid content of 2%. Then, 291 g of hot water was added to 9 g ofglucomannan (Propol A, manufactured by Shimizu Kagaku, Co., Ltd.) anddispersed by means of an Ace Homogenizer at 15,000 rpm for 10 minutes at80° C. to obtain 300 g of a liquid dispersion having a solid content of3%. By means of TK Homomixer, 280 g of the 2% dispersion ofmicrofibrillated cellulose and 100 g of 3% dispersion of glucomannanwere uniformly mixed at 8,000 rpm for 5 minutes at 25° C., to obtain 380g of a liquid mixture having a solid content of 2.26%. The mixture (44g) was filled into a wide mouth polycarbonate bottle having a capacityof 125 mL, frozen at −20° C. for 60 hours, and allowed to stand at roomtemperature to obtain a gel.

The gel strength of this gel was not measurable, because it exceeded thelimit of measurement (19.6N) of the apparatus. When it was tentativelyeaten, it was almost too hard to bite off, and, thus, could not beconsidered edible by any means.

Example 55

A lacto-ice was prepared by the use of the product of the presentinvention. Therefor, 10 parts of millet jelly was introduced into 55.45parts of water heated to 40° C. While stirring and mixing the mixture,10 parts of defatted milk powder, 10 parts of sugar, 10 parts of aqueoussuspension-form composition D (solid concentration 0.5% by weight) and0.25 part of glycerin fatty acid ester were added thereto. Then, 4 partsof coconut oil was added and the resulting mixture was stirred anddissolved at 80° C. for 10 minutes. After homogenizing the mixture witha piston type homogenizer, 0.3 parts of vanilla extract was added andaged at 5° C. for 16 hours. Then, the mixture was subjected to freezingand hardened to obtain a lacto-ice.

Although the lacto-ice thus obtained had a body feel, its mouth feel wasexcellent in melting feeling in the mouth without any pasty feeling. Itsheat-shock resistance was also good.

Example 56

A caesar salad dressing with a feeling of the body which was easy to becaught in the salad was prepared by the use of the product of thepresent invention. First, water-dispersible dry composition J was addedto hot water having a temperature of 80° C., and dispersed at 15,000 rpmfor 5 minutes by means of an Ace Homogenizer to obtain a dispersionhaving a concentration of 1% by weight. Then, into 20 parts of thisdispersion were successively mixed 25 parts of commercially availablemayonnaise, 6 parts of apple vinegar, 5 parts of sugar, 4 parts of lemonjuice, 3 parts of salt, 1.5 parts of powdered cheese, 0.1 part of sodiumglutamate, 0.05 part of garlic powder, 0.05 part of roughly groundpepper, 0.05 part of roughly ground red pepper, 0.2 part of xanthan gum,and water to make the whole weight 100 parts. Finally, the mixture wasagitated by means of TK Homomixer at 7,000 rpm for 12 minutes at 80° C.to obtain a homogenized mixture, which is then sterilized.

Static viscosity (measured with B-type viscometer, rotor No. 3, 12 rpm,25° C.) was as high as about 2.3 Pa·s; and shaking viscosity was about 2Pa·s. Regarding the mouth feel. The dressing had a intense feeling ofthe body, while it was melting in your mouth without a pasty texture.When the dressing was poured out of a container, it followed smoothly.When the dressing was stored for one month at 25° C., it kept a uniformappearance, without separation of oil and water, and without coagulationand precipitation of spices.

Comparative Example 41

A Caesar salad dressing was prepared according to Example 56, exceptthat the water-dispersible dry composition J was not used and thexanthan gum was used in an amount of 0.3 part.

The static viscosity and shaking viscosity were about 2.4 Pa·s. Althoughthe body feel was high, an intense pasty feel (uneasiness in melting inthe mouth, a paste-like feeling) was simultaneously felt. When thedressing was poured out of a container, it became a lump, and did notfrow smoothly.

INDUSTRIAL APPLICABILITY

The fine-fibrous cellulose of the present invention can provide variousfood products with a bodily feeling and stabilities (heat stability,suspension stability, etc.) without any adverse influence on the mouthfeel of the food products. Further, by combining it with a specificpolysaccharide, a gel excellent in heat resistance and a gel having anovel mouth feel can be provided. The fine-fibrous cellulose of thepresent invention can be produced from cellulose derived frominexpensive plant cell wall, by an economical process.

1. A water-dispersible cellulose, the water-dispersible cellulose beingderived from a plant cell wall having starting cellulosic substance,wherein the starting cellulosic substance has an α-cellulose content of60-90% by weight and an average degree of polymerization of 400-1300, orthe starting cellulosic substance has an α-cellulose content of 60-100%by weight and an average degree of polymerization greater than 1,300,the water-dispersible cellulose being crystalline having a crystallinityof 55% or more, and fine fibrous without entanglement between fibers,and the water-dispersible cellulose having substantially no branchedbundles of fiber, the water-dispersible cellulose comprising 30% byweight or more of a component stably suspensible in water, wherein thecomponent comprises a fibrous cellulose having a length (major axis) of0.5-30 μm and a width (minor axis) of 2-600 nm, and a length/width ratio(major axis/minor axis) of 20-400, and the water-dispersible cellulosehaving a loss tangent of less than 1, when made into a 0.5% by weightaqueous dispersion.
 2. The water-dispersible cellulose according toclaim 1, comprising 50% by weight or more of the component stablysuspensible in water and having the loss tangent of less than 0.6, whenmade into a 0.5% by weight aqueous dispersion.
 3. An aqueoussuspension-form composition, comprising: the water-dispersible celluloseaccording to claim 1 or 2 in an amount of 0.0005-7% by weight and water.4. A food composition, comprising: the water-dispersible celluloseaccording to claim 1 or
 2. 5. A water-dispersible cellulose, thewater-dispersible cellulose being derived from a plant cell wall havingstarting cellulosic substance, wherein the starting cellulosic substancehas an α-cellulose content of 60-90% by weight and an average degree ofpolymerization of 400-1300, or the starting cellulosic substance has anα-cellulose content of 60-100% by weight and an average degree ofpolymerization greater than 1,300, the water-dispersible cellulose beingcrystalline having a crystallinity of 55% or more, and fine fibrous, andthe water-dispersible cellulose comprising 30% by weight or more of acomponent stably suspensible in water after being centrifuged at 1,000 Gfor 5 minutes, wherein the component comprises a fibrous cellulosehaving a length (major axis) of 0.5-30 μm and a width (minor axis) of2-600 nm, and a length/width ratio (major axis/minor axis) of 20-400,and the water-dispersible cellulose having a loss tangent of less than1, when made into a 0.5% by weight aqueous dispersion.